I checked out the trial and wasn't too impressed. Output quality is good, colors are good but not as good as I get with Nik Viveza 2 run from LR3. There's nothing like Nik Silver eFex Pro, which to me is a workflow disqualifier. DxO's sharpening is very good - undoubtedly a convolution with a filter kernel calculated from a point spread map (aperture, distance, focal length, field position). By the same token I assume their lens corrections are first class. But otherwise I don't see a whole lot in its favor; it's pathetically slow (a minute to process a raw on my 15" MBP? come on - LR3.3 takes maybe five seconds), and it promotes a "project" based (like Windows software anno 1999) workflow. When I go add ProPhoto RGB to the process options it gives me a file browser pointing to my Documents directory, instead of a list of available color spaces. I agree with the sentiment expressed above - the UI is very clunky, if not amateurish. It functions like it was designed by engineers, not an experienced UI designer.
Can it be run as a plugin from LR3, solely for lens corrections and input sharpening? If so, I'd buy it! But as a main workflow tool... I personally didn't find it very appealing. (But, YMMV!)
DxO also has no support for the Leica M9, Mamiya ZD back, or (since I'll likely go there in the future) PhaseOne. I can't see using different workflow tools for different cameras! If I carry the M9 around the neck and A850 with 70-200 over the shoulder, shooting the same things, the last I want is for the files to end up in different workflows. Dealbreaker.