According to the german site Gamefront, the reason RE5 was not at E3 was because Capcom wants to display its PS3 lineup only when the games are fully functional. They speculate it will be playable at this year's TGS. There is also a slim chance of a demo debutting over the Xbox360 and PS3 online services around the time a hands-on version is revealed.
Seems like delays in the vein of RE4 a few year backs.
