Yeah the demo is legitimately available for download today only (well, yesterday and the day before too, but today is the last day it's available FOR NOW)
I tried it since it's only like 500MB and was very unimpressed. The graphics are nice and all, but everything feels CLUNKY. You can't move around when aiming, aiming itself just feels slow and tedious, in general the game felt like a third person shooter from like eight years ago. after Gears of War, even GRAND THEFT AUTO 4, I don't really have patience for RE5's controls and they could definitely make/break the game. To be fair, I didn't spend much time with it either, but I was pretty turned off.
WHY SO SERIOUS HAHAHAHHAHAAHAHAHAHAHAHHAHAHAHHAHAHAHAHAHAHAHAHHAA