I can't agree on the web side(asp.net, sharepoint, web parts, etc) but on the desktop (.net, c#, wpf, silverlight, parallel programming) I can't found something similar and when somebody speaks about HTML5 replacing the desktop I can't find any sense (I can hold my bet for the next 4 years.) There are few people with strong experience in many technologies to have a good argument in favor of the WEB with RIA. I simple example: there are not strong graph libraries (like Tom Sawyer, Jung) in html/JavaScript except prefuse in Flash.