As far as the keyboard, the only game on xbox 360 that can use it (so far as I know) is FFxi. Microsoft may not support Keyboard/Mice, but there's no reason why the games shouldn't. Microsoft can't dictate what controles a game can use, that would be way outside their power (which is why I don't see why Oblivion didn't have the option for keyboard and mouse, I would love to at least have that resource at my disposal). And with that I'm gonna let this debate die, it's almost turning into a flame, lol.
Do I think that Arena and Daggerfall should be ported? Most definately. gamesas isn't making anymore money off of these two titles anymore, as the only copies of them are being bought/sold between gamers and not by Bethsuda itself. The only way they'll make anymore money is to make it more availible to a wider base of players. And frankly, I think they'd make more money than they'd spend doing it. So they'd do well to consider it.
Do I think that Arena and Daggerfall should be ported? Most definately. gamesas isn't making anymore money off of these two titles anymore, as the only copies of them are being bought/sold between gamers and not by Bethsuda itself. The only way they'll make anymore money is to make it more availible to a wider base of players. And frankly, I think they'd make more money than they'd spend doing it. So they'd do well to consider it.
Actually, Microsoft can, any game wanting to released on their system has to meet certain requirements, with exceptions like MMORPGs. Epic games (creators of Gears of War and Unreal Tournament) won't release UT3 on the X360 because Microsoft won't allow users to 'cook' mods from the PC version to the 360 version.
Bethesda have probably considered it several times (since people have been asking for ports ever since Morrowind), but there are obviously lots of issues with porting it, else they both would've been ported already. It's been a nice discussion, very civilized.