IE 8 to be precise. The Beta 1 is available and offers some interesting ideas – for me the first one that jumps out is Webslices. Kind of like marking up your pages for consumption (in pieces) rather than in seperate places like RSS (is from static html).
Of course this could lead to further issues since RSS feeds can be generated from a server seperate from the web server used for the web site and I see that Microsoft have noted that with their comment below..
WebSlices is a new feature for websites that enables users to subscribe to content directly within a webpage. WebSlices behave just like feeds in that users can subscribe to them and receive update notifications when the content changes. Websites are polled at user-defined intervals, similar to the way RSS feeds are polled. Website operators may also define a minimum wait time between polls to minimize requests.
So if you fancy seeing whats coming from a development point of view you’ll find the beta and other information at http://www.microsoft.com/windows/products/winfamily/ie/ie8/webslices.mspx
Versions are there for XP (32/64 Bit) and other windows server O/S – 2003 and 2008