AROS is coming along nicely and more and more things are now falling into place.
MorphOS 2 is supposed to be coming soon and has a hardware accelerated GUI offering special effects seen on the likes of OSX, XGL linux and Vista. So far it has been shown on a 400Mhz board called Efika and from what I've seen it is very impressive.
MorphOS and OS4 both now have more modern web browser, but things like flash and embedded video are still not supported.