The PC version doesn't have good M/KB support, so I'm going to play it on consoles which also doesn't have M/KB support!
The PC accounts for what, 4% of sales? Xbox 55% and PS3 40%? The console versions are going to get by far the most development love (as per usual), so if AC3 on the PC ends up not playable with the kb/m, you're just shooting yourself in the foot buying it on this platform.
Your mistake to make, I suppose, but if even rudimentary kb/m support is too much, you've got to wonder in what other ways they will be pulling back. Sounds like it will be a strict copy and paste job to me, but Jerykk seems to think superior visuals and performance awaits him. Good luck with that one, mate - you're going to need it.