The fact that this was posted on the Google Apps blog is telling- I imagine that Google wants to roll this out to Apps users before general Gmail users. I'm surprised by the reaction in here- yes, it's an addition to the standard e-mail system. Do we really want that system to stand absolutely still? If that's the case, why are we cheering so much web browser development? Surely a browser from 1997 should be good eno…
Also I can see uses for this on business systems. Notifications are send via email, could be useful to make it possible for users to also take action in their inbox without proceeding to web.