http://xbox360.ign.com/articles/708/708327p1.html

Classic Games - Konami, Midway and Namco are putting out a nice collection of classica arcade titles for Live Arcade. Konami has Contra, Time Pilot, Frogger, and Scramble. Midway has Ultimate Mortal Kombat 3 and Defender. And Namco has Galaga and Pac-man. All these games play pretty much the way they did on the stand-up machines in the arcades years ago. Visually, the graphics have gotten and update with neater textures. But most importantly, games like UMK3 and Frogger have multiplayer features like versus and co-op. We should see these out some time later this year.