IMO the top 10 Cards in Kaladesh for our format are (in no particular order and not including the obv op fastlands):
Voltaic Brawler
Chandra, Torch of Defiance
Dovin Baan (very underrated)
Verdurous Gearhulk (very underrated)
Nissa, Vital Force
Cataclysmic Gearhulk
Smuggler's Copter
Lathnu Hellion
Scrapheap Scrounger
Inventors' Fair
Honorable Mentions: Kambal, Fleetwheel Cruiser
Veteran Motorist - 2cc 3/1 scry 2 imho kinda nice
Kambal, Consul of Allocation - 3cc 2/3 creature with kinda 'Pyrostatic Pillar' effect - Combo Breaker
Saheeli Rai - 3cc planeswalker, maybe will find some play in aggressive URx decks
Key to the City - dont know yet how this card will perform, but wanna try it in my 4c Blood
I will not adhere to the "Top 10" label but instead go over the full set. Here are my thoughts on the new cards:
I am absolutely certain that two Kaladesh cards will see play:
Verdurous Gearhulk and Torrential Gearhulk - Especially the green one is immensively powerful at almost any given board state. The blue one is more volatile in his power level. Sometimes you will be able to cryptic command a spell and get a 5/6 for 4UU and sometimes you will only get a bolt. His power level is strongly dependent on the board state and the contents of your graveyard.
The fast lands are kind of obviously good for agressive decks in those colors.
Cards that might see play:
Dovin Baan - Looks solid but on careful inspection the problem is not his own power level but what he competes with in the four mana PW slot in those colors. Elspeth, Jace the Mind Sculptor and Jace Architect of Thought are much better. Maybe J,AoT is actually worse or on par and you can play Dovin but in UW you have more problems with someone going wide with small creatures than having a singular medium sized threat.
Chandra, Torch of Defiance - She is solid as well but again competes with superior planeswalkers in this slot. Note that you can not play lands you reveal with her. For RDW you want immedeate impact larger than two damage. For Blood you want to add board presence so you rather play Garruk/Xenagos. Izzet has the Jaces. Most decks do not care about the two mana, paying four to torch a creature is underwhelming, the "card draw" can not put lands into play and merely deals two damage to players.
Smugglers Thopter - A really good card. Gives a relevant flying body and card cycling to creature decks that is wrath-proof. Mono Red does not want to play too many creatures, so this is more of a WW or UW Skies card to enhance the draw and gain some evasive damage to smuggle in the last points. You can tap creatures for it that would not get through in the mid to late game or give their damage pseudo haste.
Nissa, Vital Force - 5/5 is enormous, especially until your next turn, and she threatens an ultimate, that will win grindy matchups, on the turn after she hit play. Or she regrows your best card from the graveyard if you need immedeate impact. Looks like an allover great card. Five mana is not nothing in HL but she surely brings the necessary force to make it worth it.
Veteran Motorist - Good aggressive stats and scry two. But since you will most likely not crew anything in HL and Depala, Pilot Exemplar is not a factor, he might just be underwhelming. There are anthems though and he is very very cost effective.
Voltaic Brawler - This seems good. A two mana 3/2 that attacks as a 4/3 trampler twice is something Gruul Beatz might be interested in.
Foundry Inspector - Cost reductions are always possibly powerful.
Key to the City - Without madness or graveyard synergies this probably does not make the cut. But the ability to push through damage and filter cards is a possible key to victory.
Scrapheap Scrounger - If there was an agressive black deck, this would be amazing. But since there is none as far as I can tell, this is just worthless scrap.
Skysovereign, Consul Flagship - It does a nice Flametongue Kavu impression, has a moderate crew cost and is a huge flying threat. If you can you will probably play Thundermaw Hellkite or Stormchaser Dragon over it or not reliably be able to either get the five mana or crew it. A powerful card that probably has no place to go to.
Inventor's Fair - A good card in decks that can get three artefacts into play reliably since they probably have big pay off artefacts as well.
Cards that are on the fringe:
Filigree Familiar - An overall good package but worse than Kitchen Finks if you are in White and/or Green.
Aerial Responder - Skies decks could be interested but they probably try not to play three mana creatures with two power.
Noxious Gearhulk - If there is something to hit, this dude is awesome. If not, he is an expensive crature. Highlander has enough decks that do not play creatures and a lot of those that do can go under it.
Brazen Scourge - 3/3 for three is relevant to RDW but again the problem is what it competes with in that slot. You rather have Ball Lighning, Hell's Thunder, Chandra's Phoenix and Boggart Ram-Gang in that slot. And that slot is small and hotly contested. There are still three mana utility guys one might want to play over it (Chandra, Fire of Kaladesh, Zo-Zu, the Punisher, Magus of the Moon). If you are interested in more, he probably fits the bill but since at the moment the burn heavy RDW versions seem to be better I brazenly assume this will not be the scourge of the format.
Blossoming Defense - If you are in the market for tricks this is a good one.
Kambal, Consul of Allocation - This is a hit or miss card. Against aggressiv Decks this is way too small to have an impact and against controllish decks this is not guaranteed to live long enough. Against combo this is absurd. They usually lack the removal and are prone to kill themselves over time unless it is a two card combo or reanimator. I doubt this will make the cut though. There are just too many decks that do not care about the effect or the body.
Rashmi, Eternities Crafter - Every first spell you play on every turn has a one card chance of cascade or cantrip. That is insane value no matter what kind of deck you play. But four mana usually needs to do more than be a 2/3 that pays off after you untap. But when you untap with this in play it should be absolutely bonkers.
Cards that are overrated or just not good enough:
Cataclysmic Gearhulk - Apart from dream scenarios the fact that it costs five, that Highlander decks usually play at least creatures and planeswalkers and that it does not hit lands makes me think this is a cataclysmic failure. Yes you might get them to one creature and keep two but the fact that they decide which ones to keep and that they can usually keep on going makes it not worth it. Some rare matchups make this great. Workshop decks that have not managed to lock you out or combo until turn 5/6 lose most of their board. But in most other cases this will hit their already outclassed creatures and is horrible if you have two planeswalkers or a mana artefact and a creature etc.
Insidious Will - All modes on this card are really good. But four Mana is too much since countering a spell will be the default mode. Highlander values flexibility but not at such a cost increase. If this card was 1UU it would be nuts.