I love the DX and all of the advanced features it has. I jumped from a 6 year relationship with Blackberry and BES. During work hours I miss my BB other than that the DX is cool.
Android has a lot of work to do to catch up with Blackberry in the enterprise and Blackberry has a lot of work to do to catch up with Android and iOS in the non-enterprise market.
I don't know how quick I would count bb out. If you care about tight integration with MS Exchange, Android and Apple do have a long way to go. And there is a big market out there, for both sides.
I has become a love hate relationship, with me and this DX. It is a cool phone. Just rest on what your primary use will be.