In classical mythology, Atlas bore the weight of the heavens and the earth on his back. If you don't want to share his fate, you should be at least a bit careful about deploying the new ASP.NET "Atlas" technology that Microsoft has been trumpeting lately. Although it's bright, shiny, and state-of-the-art, it's also pre-release and not right for every project. So before you pick up that globe and start lifting, take a few minutes to understand what you're picking up and why you might want to use it.
But what about the dark side of Atlas? As with most other things in the development world, there's no free lunch.
Finally, you'll notice I said "release version." In case you missed it, despite all the hoopla Atlas is still pre-release as of this writing. Which means, of course, that anything you develop using the current version will quite possibly need to be redeveloped, or at least tweaked, when the final version comes out. It's all very well to be the first one out of the gate with new technology, but you need to allow time in your schedule for the nearly-inevitable rework.
Now, all that aside. Do I think using Atlas is a good idea? Heck yes -- for some sites. When you have a site that can really benefit from client-side techniques such as confirmation dialogs and collapsing panels, and you can come up with a good way to "gracefully degrade" the experience for browsers that don't support Atlas, when your schedule allows the time for testing and potential rework -- go for it! Just don't treat this, or any other, technolgy as magic pixie dust that you can sprinkle on your applications to make them instantly better without any potential drawbacks.
Mike Gunderloy is the Senior Technology Partner for Adaptive Strategy, a Washington State consulting firm. You can read more of Mike's work at his Larkware Web site, or contact him at MikeG1@larkfarm.com.