http://cube.ign.com/articles/541/541561p1.html

Nothing too detailed but here are the more interesting tidbits:

- Games are being emulated instead of ported

- Gamecube version is the furthest along, with most of the games running at full speed or faster than the arcade originals

- PS2 and Xbox versions aren't as far along

- A new "DNA" interface is where you select the games(much better than the kind of generic interface from the original Midway Arcade Treasures)