Other
OpenSocial Explained in Five Sentences - Dare has some haterism in his game. He may be right, but he's been pushing back on OpenSocial pretty hard imo.
Click Here? - Jeff posts some thoughts on hyperlinking. 1, 6, 10, and 11 are my huge pet peeves. Particularly 1. I HATE when I have to precisely aim the cursor to catch the link, or even worse, move it around slowly trying to find the hitzone.
Development
Everything about REST Web Services - Pretty solid intro to RESTful web services, at least in concept.
SharePointPedia goes live
The Gospel of the GUID - I typically use GUIDs as well, at least for volatile entity-mapped tables, but for the love of <Deity> don't use them as your clustered key.
Rhino Mocks + Ext. Methods + MVC == Crazy Delicious - it's no Mr. Pibb + Red Vines...but still cool.
Versioning with Cruise Control, Nant, and Subversion
MVP Part 2 - Passive View - (Also make sure you have read Jeremy's Build your own CAB series, which includes a wealth of good information on MVP and, well, a lot of stuff.)
SubSonic: MVC Preview Video - Just started getting into SubSonic on a new project, and I like it a lot. The videos are a great touch Rob.