I just noticed this question in the comments section
my post about this screencast on our team blog. I thought it might be valuable to share with those who find this screencast through other means than the blog.
Question:
"I've already worked on this kind of development, and i'm impressed with Visual Studio JavaScript debugging facilities...
Is it standard with Visual Studio 2005?"
Answer:
"Yes. It's a little known feature of Visual Studio / IE. It is not enabled by default. Just go to Tools->Internet Options (in IE). Then go to the Advanced tab. Make sure both "Disable Script Debugging" checkboxes are unchecked. Now set a breakpoint in your JavaScript. You should now have JavaScript debugging enabled. It definitely makes JavaScript programming a little more productive

."
-Marc