The IETeam is Locking-down IE7 meaning that once it is locked nobody can touch it because it has gone through all the standards testing and has come through clean. There is always the change that somebody will find something, but this will happen after it is launched.
The launch will come as a Critical Update from Windows Update Service. If you don't want IE7 then you had better download IE7 Blocker soon because there is no telling when it could be released.