Lite Microsoft ajax att titta på. Seadragon hjälper dej att implementera stora bilder med zoom för stora bilder!

Silverlight Toolkit - Great sets of part for building Silverlight Applications  (MS developed)
Silverlight Contrib -  Contribution to the silverlight
Ajax Toolkit -  Well most downloaded but it is great
Dropthings - Ajax webb portal
Svchost Viewer -  Let you see what all those svchost are doing

Coollite has done som work aspifying the EXT javascript framework. It's worth a look.  Would be nice implementing this into blogengine admin.

Scott posted that they will ship jQuery with visual stuido! This is something realy good and a first I think. Correct me if I'm wrong. 

I'd just hope that the community, will not loose any contributers cause of this. I use jQuery and I like it..allot

also read the blog from jQuery