Directly from IE Teams Blog,
There will be a navtive XMLHTTPRequest object in IE7. It is definatly not in Beta 1, so lets hope it is in Beta 2! I would love this to be in ASAP because I keep running in to security issue having to always insure that browsers are set up correctly for ActiveX.
On a side note, it is also amazing to hear that they are producing a SELECT input box that can be layered properly!!! hopefully it will also be able to be styled better.