I'll clarify, now that I'm a bit less livid...
We are actually in fact allowed to merge code before it is released, but not before it goes into Release Candidate and VMM is in RC right now. However for our own sanity we cannot sensibly merge code out of the order in which LL releases it. We also rarely know what order release candidates will be released in and since there are usually more than one RC on the go at any given time we generally have to wait until LL actually releases it before we can merge it to our working repository.
Once we have VMM merged we're going to go straight into release mode, cut a release branch and code freeze for all except blockers. We're going to really push for an intense QA cycle and I'm hoping we'll be able to issue a preview build to our preview group within 1 week from the time we get a beta out to our QA team. Merchants will be able to use that preview for VMM but the key word here is 'hoping'. there are no guarantees or promises that will happen and the reality is that there is still no chance we'll have that available before the 23rd either.
On the bright side... LL has done a LOT of work and testing with VMM and at least initially it looks very good. They seem to have done it well this time and the system, if it works as planned will be a very good system in the long run. I think Merchants will like it.