Rick Strahl is writing about his experience about the new Atlas files:
Ok, here goes. I’ve had one hell of a frustrating day going through my code and moving it to Atlas Beta 1. I’ll get into specific issues in a minute, but my overall feeling is that this build is REALLY BUGGY. The previous ATLAS CTPs were reasonably stable and handled errors gracefully forwarding them to the client code. This build just crashes hard in many cases deep inside of client framework code. I’ve been at it for the better part of the day and while I managed to port all of the samples, just about all of them have one or two issues that I cannot seem to resolve completely without removing functionality. In fact, I've been doing that alot - skipping using framework features instead resorting to lower level JavaScript because it works.
Here’s more detail [1].