Both the xbox cpu and the xbox 360 cpus are as general purpouse as they get. They are all pretty much off the shelf parts.

What I want to know is (time to get down and technical):

Does xbox 360 support streaming off samba shares, or windows media center only?
Does it support mp3?
Does it support divx/xvid? some of the most popular formats after all
How about quicktime?
h264?
will it support the dvd changer in the future? it sounds excellent
how about playing media of the harddrive? does it support the same formats there?
how about an external harddrive?
Entering text with a usb keyboard? would require minimal programming effort to support

There's no reason for it to not support mouse/keyboard now that it uses standard usb.