jQuery vs MicrosoftAjax in ASP.NET MVC

Question

Under what circumstances would you use MicrosoftAjax over jQuery in an ASP.NET MVC application?

According to Scott Cate in this podcast Object Oriented AJAX with Scott C

Answer 1

jQuery is lighter-weight, easier to integrate into standard javascript functions, and has great community support. MS Ajax is heavy, but I suspect they are rewriting everything AJAX.