The hotfix mentioned in a previous post of mine among the things that it fixed, was an intellisense problem with JQuery.
I started newly working with JQuery and seems a promising library. Jeff King has some additional tips and tricks on the integration of JQuery inside VS 2008. You can read more here:
JScript IntelliSense: Working with jQuery
There is also another blog post I find useful for the IntelliSense of jQuery in VS 2008:
Intellisense for jQuery in Visual Studio 2008
Hope this post helps,