Coming this week (tomorrow). Here's more from Om Malik and the WSJ (sub req'd). Bit by bit it appears that Google is building a competitive, web-based Office alternative (and not adopting Open Office).
Schmidt & Co. have recently said "we're focused on search." But this is not search; it's another non-search application, like mail or calendar (that will no doubt have search embedded in it). Why do this? is the really interesting question from my point of view. More loyalty/usage = more ad inventory? Clearly this isn't about ad inventory really. It's almost like Google can't help itself in some sort of involuntary, inexorable drive to be "the network" or be to the Internet what MSFT has been to the PC desktop to date.
Here's what I wrote about Google + Writely when the deal was first announced, about a larger potential vision combining low-cost computing, free ubiquitous access and online storage and services.
Lots more detail from Danny Sullivan.