
The new message preview feature transcribes the voice message into text and includes that in the e-mail. You now have the option to prescreen your voice mail without ever listening to the message. Of course you still have the option of playing the WAV file or playing the message on the phone, now you can add the ability to read a bit of the e-mail and deal with the message accordingly. Now that's convenience!
Outlook 2010 and OWA 2010 users can also take advantage of the Voice Routing Rules. This allows the end user, yes I said end user, to choose how they want to handle voice mail messages. For example a user can create a routing rule based on the incoming caller then route the call to their mobile phone. Numbers that don't match can then follow an auto-attendant to route the call to an appropriate team member.
Think about, you're on vacation when an important client calls with a giant purchase order burning a hole in their pocket. How cool is it to be able to setup a rule so your customer can locate you and close that important deal? Microsoft offers a live demo on the TechNet Edge site under What's new in Unified Messaging in Exchange 2010?
It's really worth a look.

More information on Exchange