I'm sure the escapist had a news article not long ago strongly suggesting (if not outright stating) that there was going to be a Halo: Combat Evolved remake sometime this year.
Either way, i'm betting all my chips on it being so. The original Halo title was practically the flagship for the xbox console and has earned unequivocal praise as being the 'daddy' of a lot of modern shooters. (Yes, that's the game that invented the 'two-weapon only' rule) The xbox didn't exactly have such well-acclaimed hits after that, aside from Timesplitters, but even that was just riding on the success of the PS2, as i'm sure the first Timesplitters game originally came out for the PS2 - then they moved on to TS2 and Future Perfect. I'd actually love a Timesplitters remake. Or just a new Timesplitters full stop.
There's a lot of cult titles i'd really like to see remade... anyone remember Bloodwake, Yager and Scrapland?
Oh, and don't forget Beyond Good and Evil is being remade in HD too. (Though i've played and beaten it so many times that it's not worth re-experiencing again)