Arkose: The bow upgrade is a strange choice. Garrett's primary gear has always been ordinary or magical, with technology reserved to secondary equipment like flash bombs. It's also clearly more showy than practical (the condensed form is still very bulky) which has never been Garrett's thing.
I hope they don't overdo it in an attempt to make Garrett more marketable.
Yeah, this bothers me a bit. One of the main reasons, imo, the Thief series is awesome (especially Thief 2), is that you really feel like a thief. All of your base equipment is pretty simple: Dagger, blackjack, bow, etc. The tech-y stuff is, as you said, mostly one-time limited-use stuff like flash bombs and scout orbs. And, as other people said, it does seem a little too "Heh, look how cool I am" on the part of Garrett (though I suppose it's possible it's not Garrett, but a younger "edgier" new main character would probably be even worse).
Pemptus: Also, Thief 4 is supposed to have multiplayer and it's supposed to play a big part.
Could you provide a link? Because that's really depressing. The one way I could see multiplayer Thief working is if you all play thieves in a large map and have to race to collect a certain amount of stuff or complete an objective. This could be a lot of fun (and would encourage alternate strategies, such as ghosting so there're more guards for the other players to deal with). Alternatively, it'd be interesting if one team were thieves and the other were guards.
Anyway, I'll reserve judgement until we see some actual gameplay. At the very least, I can't see them making it purely third person. They may do something where you can switch like in Thi3f (which, incidentally, makes more sense then Thi4f), which was alright. I liked the body awareness, even if it was a little weird at times, and you can just choose to ignore third person if you want.