One among the many new features of IE 8 Beta 2 is in the search bar, in the form of Auto Suggest. This new feature, built into IE 8 Beta 2 for seamless experience has some great cross Search provider features as well. To start, type something into the search bar at the top right of Internet Explorer. A list of suggestions drops down, including most popular suggestions and also a list of suggestions stemming from your browsing history.  But to get the full effects of the feature, add in some other Search Providers.

and then run a comparison between search providers, or narrow your search to Wikipedia (or eBay, or Amazon, etc).  This way you can leave your default at Live Search but check results in other browsers, for example.  A really nice little feature, now built in to IE 8 Beta 2. 

More info: Search Providers

And it looks like this same functionality may soon be coming to Live.com. One additional note on IE 8 (thanks for the tip, Chuck!), this from the XP download release notes:

Windows Live Mail

Internet Explorer 8 Beta 2 and Windows Live Mail are currently incompatible. If you install Internet Explorer 8 Beta 2, Windows Live Mail will crash when you create or reply to an e-mail message. No workaround is currently available.

Source:→ LiveSide