We expected this, but Microsoft has confirmed that there won't be anymore Windows 7 beta releases. Just the hot little release you're playing with.
There will be a followup (possibly private) release candidate, which "will be Windows 7 as we intend to ship it." Any changes from it will address "only the most critical issues that arise." And then boom, release to manufacturing and on store shelves.
They're so far not spilling the date for the release candidate, which is the info we really wanna know, since it'd point to a launch date for the final. That said, most sources point to July for the final release, and this confirmed streamlining of Windows 7's milestones—made possible in part by the vast amount of data Microsoft has gathered from the wide beta releaes—supports that. [Engineering Windows 7 via ZDNet]