So I played the demo last night.
WOW. That sums it up pretty well.
This is what Resident Evil 5 should have been. I can honestly say I had more fun with this demo than I did with all of RE5.
It really is what the fans were asking for: keep that RE4 feel but incorporate the classic RE feel at the same time. Mission accomplished. "This door won't open for some reason..." "Do you want to empty the tub?" CLASSIC!
I tried to play in 3D (and even cranked up the special Revelations 3D in the options), but it just made my head hurt and looked bad in motion, like usual. But it looked really good in the cutscenes. Although I won't be playing the game in 3D, I think it's safe to say it has the most effective 3D effect out of any 3DS game.
Basically, I can't wait to get my hands on this. I'll be there day 1. This is the true RE5, and I hope RE6 follows in this game's footsteps. Assuming the game doesn't go all action-y, and the only horror was contained in this demo =P
My only nitpick: the game really does feel trapped on that tiny 3DS screen. I hope they release it in 1080p on the Wii U along with other 3DS games, PSP to PS3 style. That would be great.