QUOTE(edwinmcdunlap @ Apr 12 2011, 12:30 AM)

Why not just port XBMC?
XBMC is, at it's core, a ported Mplayer, with an advanced GUI, networking system, etc. It's a huge bit of code, and it's designed for x86 architecture (remember, every port of XBMC that exists in non-alpha or proof of concept stages, is standard x86, from the Xbox's modified 733Mhz Celeron processor, to the x86 linux ports, and windows ports, etc). Easy to port around to other operating systems so long as the core architecture and hardware on those systems is similar enough.
Now the Xbox 360 has a PowerPC core - very significantly different from the original Xbox (think older Mac computers, running G4's as a general example). Rewriting, or porting, XBMC for PowerPC is a monumental task. What's being done here is the first steps towards such an idea (though the end result, I'd wager, won't be XBMC 11, or whatever version they may be up to), though it will be more a spiritual successor than a direct "port." Mplayer, the core of XBMC, is a basic video player with a huge array of codecs built in. The first step, here, is to port the individual codecs, keeping them open source allowing the homebrew community to make use of them, and provide a large base to work from.
This is a great step forward. Though it may seem like a complete rewrite of XBMC, what is being done here can easily be added to the already existing architecture of FSD's media player, or just put it into its own shell. Remember, XBMC itself started out much smaller and much less ambitious in nature than the behemoth that it has become. Before XBMC it was a the much leaner XBMP (Xbox Media Player), and before that it was YAMP (and one other whose name eludes me). Each project was a large task in and of itself just to see the basic concept of playing video on the original Xbox, then straddling more formats, then giving the user a better interface, and so on.
Remember, baby steps. In order to achieve any lofty goal, one must have the pathway laid out before you before you can make progress.