Thanks for your comments, guys. I think you raise fair points - not all employers invest in their teams, which means that many people have to train themselves. What we're trying to do with the new certs is to get them out at release wherever possible, and sometimes even earlier. As you say, @aL3891 - if you want to be ahead of the curve then beta is a great time to be doing skills development; but if at the very time that companies are looking for those skills you can demonstrate that you have passed a rigorous exam focusing on that area, you're going to have an edge in the jobs market.
Similarly, if you have the skills, you should be able to pass the exam already - you don't need to go on a formal training course. If you're a great ASP.NET developer, you should pass the new exam with flying colors; on the other hand, if you have a poor understanding of the technology and rely on MSDN as a crutch rather than a reference, you're going to have a hard time.
Imagine hiring a web developer today - everyone and their dog has HTML5 on their resume. Sure you can quickly sift through the dross when you get to an in-person interview, but if one of your candidates had passed an exam worthy of the name, you'd know ahead of time that they had the technical skills - which ought to ensure that they got an interview at least.
That's what we're going for - certs that measure real on-the-job skills, that have a good enough reputation in the market that employers look for candidates with that level of accreditation.