This will be interesting, now.. One of the big things the DI had going for it was that it would release simultaneously with 4e. The VTT is now going to be giving 3rd party applications that cover similar stuff time to get 4e specific tools and aids written in, in order to better compete.
In other words, a year ago, we thought the VTT could kick butt because it was rules-complete and official, with the inside info on 4e fueling its development to make it ready to roar out the gates fully featured on 6/6. Now, it's giving its competitors time to be more competitive, and losing its insider edge.