I voted yes as long as the game doesnt get dumbed down because of it. Im an old console player that recently got into PC gaming, i played UT on DC, UC1 Xbox and I recently got UC2.
Earlier last year i got me a nice gaming PC and picked up UT2004, and I must say WOW!! Console players just have no idea what they are missing, everything from the maps, mutators and mods,to all the customization you can do with your FOV, custom crosshairs and other stuff.
I actually would rather get UT2007 on PS3, if it's cross platform with PC community and if I could use a mouse and kyb. why? Because honestly I dont wanna go out and spend $1000 or more to upgrade my now old video card FX5900 XT to a newer and yet still old AGP video card and a faster CPU than my current AMD 64 3000+ socket 754.
Id rather spend $300-$400 on PS3 and enjoy nearly all the benefits PC players have.
I remember UT on DC actually supported both mouse and keyboard and controller, while it wasn't cross platform like Q3 arena on DC, UT DC was actually considerablly balanced between MS and KYB users and controller users. They compensated by giving a touch of auto aim for the controller users.
So this actually could work, if well thought out, planned, and properly implemented. Considering Xbox's closed network for Xbox Live, this seems as more of a possiblity between PS3 and PC rather than Xbox 360 and PC (although i have heard some stuff about PC and XBL cross platform through XNA and Longhorn). Considering Microsofts and Sony's rivalry I would HIGHLY doubt PS3 and Xbox 360 would have ANY cross platform titiles other than FFXI.