I'm not going to go over all the new features like dual core etc, there's plenty of info already out there for you to find.
However I did want to mention briefly a couple of the new Enterprise level features that in my opinion mean you might want to reconsider using a Windows Phone within your business when WP8 arrives.
It's apparently not full blown BitLocker but is derived from it and uses secure keys.
Having a secure phone platform like that "out of the box" is certainly a huge plus in my opinion.
Another couple of great features are around the custom app store and the ability to bypass the app store and presumably push apps to the phone via either or both Intune and Configuration Manager.
Speaking of System Centre 2012 Configuration Manager, it might be a safe bet to say that we may see a native configmgr client agent become available for Windows Phone 8, unless Microsoft decide that Intune becomes the preferred management platform.
I'd also like to know if that picture of the "Company Hub" is just a mock-up or not. If not then it would be interesting to know what System Centre integration we might see with the alert center and ticket status parts of it.