I like what I see. Should I get it?
Would I be wrong if I think it's similar to Diablo 2?

Yes. As far as I understand it's more Baldur's Gate, not Hack n' Slash like Diablo. More than that it's supposed to be quite a wordy / talky RPG from what I've seen.

Yes. Totally wrong in fact. The gamecard reads among others: "Challenging, classic RPG combat: Tactical real-time-with-pause combat with new party-driven mechanics and modern presentation". Expect it to be like any other Infinity Engine game or Pillars of Eternity. Yes, you should get it if you really want it. But if you'd like my opinion, don't pre-order it. Wait for the release day. Unless you value the preorder items so much.

And it's not the first time I see someone making that mistake. I guess it's just something about the isometric perspective and the dark fantasy world that immediately makes people go "oh, it's like Diablo!"

Thanks guys. I'm sure it's a great game, but not for me.

If you want Diablo-like you'd better get Torchlight if you haven't already.

Get Rune! :D