A few people have mentioned this Traffic Information site on their blogs. This has been created using AJAX and Atlas, and is a web application hybrid or 'mash-up*'. The interesting thing to me though is that it works equally well in Firefox as it does in Internet Explorer, which hopefully provides some evidence that Atlas is meeting the promise of cross-browser compatability.
The great thing about reading blogs is finding other people's blogs, the less great thing is finding time to read them all. However, if you do have time then I've a couple of interesting ones gleaned from Robert Scoble's blog. For those with any interest in Windows/Linux interoperability then the new blog from the Open Source Software Lab, Port 25, may well be worth checking out. If you have any interest in the .NET framework then the guys who brought you the class libraries can be found at the BCLTeam's WebLog.
Edit: Personally I'm not too keen on the phrase mash-up to describe this sort of application. Cool in the world of DJs and turntables maybe, but trying to apply their words to web development seems a bit forced and silly. Alternative suggestions welcome :)