The idea of a complete desktop in a browser is intriguing. Using remote desktops and virtual PCs is close. But I like the idea of just going to a URL–the “cloud” desktop. Something akin to GotoMyPC but without the need to actually setup the PC in the first place.
Two “web-friendly” implementations worth exploring are eyeOS and silveos.
Silveos is written in Microsoft Silverlight (which brings the fun back to development—IMHO). To see silveos in action visit http://silveos.com/
Other sites to check out include:
and for a list of more web operations system bookmarks visit http://www.xmarks.com/topic/os_online