jQuery is going to be a part of Visual Studio. This is a great, and I must say, an unexpected development of things.
For me personally, who’s already using jQuery along with ASP.NET, the main difference will be the intellisense annotation support for jQuery. This will be a welcomed enhancement of my development environment. Needless to say the asp.net team at Microsoft will also build ready-to-use controls in the ASP.NET AJAX Control Toolkit that builds upon jQuery.
According to Scott Guthrie there will be a free download with the jQuery Intellisense support in a few weeks. The ASP.NET MVC download will also contain it and the jQuery library.