Sure. The biggest change is that it's moving from object marking to bitmap marking[1]. This makes it CoW-friendly, which should make forking far less painful (and much faster; copying all those memory pages takes time!). Bitmap marking can take advantage of parallel marking; Narihiro Nakamura (who did the new GC work for 2.0) has said in an interview[2] that as a result of parallel marking, he's managed to reduce GC time by 40% on dual-core machines, and the hint is that it may be possible to reduce it even further on machines with more cores.

I don't have benchmarks to share, but Nakamura is a very smart guy, and if he says he can get it, I have no reason to doubt it.

[1] http://patshaughnessy.net/2012/3/23/why-you-should-be-excite...

[2] http://www.infoq.com/news/2012/01/bitmap-marking-gc