Any upgrade of a core service such as Email shouldnt be undertaken lightly - this article provides a great starting point for solution designs. For those that havent yet made the jump to virtualisation this should serve as a well meant nudge in the right direction.
The only concern I do have is the impact on other transport applications such as AV and Email Release packages - does this mean that vendors will need to have significant code upgrades to support 2010, obviously AV/Filtering that takes place outside of the environment can still route via SMTP, but there are already a number of products that interact with the transport services and will undoubtedly have issues. (I wonder about the support for Stirling for 2010 - how far in step are the product sets)
Keep up the good work - even if you dont get significant feedback we're listening!
Microsoft
