I blogged earlier about VS 2008 SP1 crashing silently when pulling up a web form or master page designer.
KB963676 is what I have been waiting for. It was made public just last Thursday on 2/26/2009, and the hotfix fixes the crash for me.
The KB description is as follows:
“Uploading both MSI and CBS
CBS Package Request for DevDiv Servicing# 592189
Exchange: Fatal Execution Error in W3WP with .NET 3.5 SP1 – crash in the loader – DomainFile::FinishLoad”
If you are behind on your hotfixes, I would also recommend the following three: KB958481, KB958483, and KB958484.