The real reason for the PR like speak is what he says in the blog post. They don't want to end up with the WinFS like fiasco where they over promised but under delivered.

MS is still ridiculed about WinFS.

Wait for the engineering blogs to actually start. They will have the real meat like the Windows 7 engineering blogs did.

http://blogs.msdn.com/b/e7/

Is there something like this for OS X or Chrome OS ?