The downloads of the IE8 Beta 1 which was released by Microsoft at the Mix 08 conference, are available for Windows Vista and Windows Server 2008, x64 versions, Windows XP (SP2) and Server 2003 (SP2) as well as XP x64 and Server 2003 x64 .
Some of the details of the latest version are given below.
A second innovation appears in the middle between news feeds, widgets and Firefox's live bookmarks. If the user adds "WebSlices" to his favourites bar, he can click it to have a quick look at the weather forecast and stock exchange prices. This favourites bar was previously known as the links bar: it offers space for news feeds and references to local documents, as well as bookmarks and WebSlices. Web designers can identify an area on their sites as a WebSlice by giving it certain class attributes - very much in the spirit of microformats.
Perhaps IE8 will give a strong push to the development of Ajax applications. New functions tackle the problem of navigation and connectivity; IE8 implements DOM storage, a storage mechanism specified in HTML5 that Firefox already knows about. That could offer a range of functions for storing offline data, similar to those of Google Gears. IE8 will also allow Ajax links to other domains; how the browser will solve the possible problem of security is not revealed in the documents so far published.
IE8 has borrowed from its competitors the feature of restoration following a crash, to enable work to be seamlessly continued, with a previously open tab for example. Microsoft claims as its major innovation the improvements made to the phishing filter introduced by the previous version. Bugs with HTML compatibility and with the DOM functions are said to have been eliminated, a known memory leak is said to have been closed, and speed is claimed to have been increased overall.
Source: HEISE Online
Michael Muchmore has also written a very comprehensive technical review. You can read it on PCMAG.com .