Mark Wilson’s blog has the best summary I’ve seen on what’s coming in Exchange 2010 and what’s new in Hyper-V R2.

The big thing in Hyper-V R2 is live migration. The big thing in Exchange 2010 is, well:

For me, it seems that Exchange 2010 is not a major upgrade – just as 2003 was an incremental change built on 2000, 2010 builds on 2007 but, nevertheless, the improvements are significant.

says Wilson. Microsoft’s product releases (irrespective of whether the main version number is incremented) can often be categorized as either a major release, or fine-tuning, and it seems that Exchange 2010 is in the latter category. Not a bad thing, given that there was a lot for admins to learn in Exchange 2007. Still, there is a lot in Exchange 2010 if you are excited about compliance, auditing and rights management, as well as some interesting new storage options:

In what will be a massive shift for many organisations, Microsoft is encouraging Exchange 2010 customers to store mailbox data on inexpensive local disks and to replicate databases between servers rather than using SAN-based replication.

There’s also no sign yet of Exchange moving to SQL Server rather than its own Blue JET Extensible Storage Engine. Confused about Red JET, Blue JET and Exchange? Roger Jennings wrote an extensive discussion of the matter.

And what of the VSS plug-in that enables Exchange-aware backup without purchasing a 3rd party solution? Promised in June 2008, still not delivered. I will be interested to see if it arrives with Exchange 2010, expected towards the end of this year. It’s no longer an issue for me personally; I’m using the old NTBackup copied from 64-bit Windows Server 2003 and it seems to work fine for this purpose. The reason Microsoft does not care about this is that most users are either enterprises, which are meant to use Data Protection Manager, or small businesses with Small Business Server, that has its own backup solution. That does not excuse broken promises.