It's me again, ole' yesterday's-news-Harms zum Spreckel, reporting that our final Exchange Server 2007 exam (70-238) went live in mid-July. This means you can now earn the MCITP: Enterprise Messaging Administrator certification.
Kate at You Had Me At EHLO (btw, Exchange team, You Had Me At 'You Had Me At EHLO'...) recently posted an excellent, first-person take on the new certs and paths. If you know anyone considering Exchange certs, point them here.
I have it on good authority that the prep guides for 70-236, 237, and 238 are being updated now to show what's current on training material--and we'll publish a certification landing page for MCITP: Enterprise Messaging. So we've got that going for us.