“Internet Explorer 7 improves the implementation of the XMLHTTP Request as a native Javascript object for rich AJAX-style applications. While Internet Explorer 6 handled XMLHTTP requests with an ActiveX control, Internet Explorer 7 exposes XMLHTTP natively. This improves syntactical compatibility across different browsers and allows for clients to configure and customize a security policy of their choice without compromising key AJAX scenarios.“
Links:
Internet Explorer 7 Beta 2 Preview, Technology Overview (.doc) :
http://www.microsoft.com/downloads/details.aspx?FamilyId=B2AC8F30-2D88-45B6-90AE-ED266161F463&displaylang=en
Internet Explorer 7 Beta 2 Preview download : http://www.microsoft.com/windows/ie/ie7/ie7betaredirect.mspx
Go get it !