Kalen Delaney's first DVD on SQL Server internals is available for viewing online. More details here.
Connor Cunningham, formerly on the SQL query optimizer team, is now blogging at SQL Skills and is whipping out posts on optimizer related topics at a frantic pace. Check out the latest here or all of them here.
Dan Jones rebuffs the idea that SQL Server 2008 is a "dot release".
CTP6 may or may not be coming soon. Chris says that CTP5 will be given away at the HHH launch. This is in contrast to the "feature complete" CTP that was mentioned in the roadmap but who know...
Mario B has raised some eyebrows with his post on scheduler troubleshooting and SOS_SCHEDULER_YIELD waits and the possibility that is is not CPU pressure always. Linchi posted about it here and then SQLServerPedia posts shortly afterwards. Anyway, check out Mario's tools.