Adobe released a beta build of Flash Player 10.1 available here: http://labs.adobe.com/downloads/flashplayer10.html
It is said that the new version of flash player offers hardware acceleration with video playback. I don’t know if they’ve also optimized a bit on what causes us lag here (cpu bottleneck dealing with massive amount of sprites when it can be dealt with much more efficiently through gpu). Have anyone tried it out yet? Does it help with making GC:C0 smoother?