Developer András Velvárt has posted some interesting date regarding which devices are using his popular alternative browser SurfCube (which just had an update). While we don't see many mystery devices on the list (nice to see the Lumia 900 though) we do get an idea of device breakdown and popularity.
The Nokia Lumia 800, arguably one of the most promoted Windows Phones yet is really gaining traction. In fact, it's number one with nearly 14% of usage on SurfCube. That's compared to the HTC HD7 at 11.7% and the Samsung Focus with 9.3% which is astonishing because as you can figure out, those devices have been out much longer than Nokia's offering.
There should be little doubt that Nokia's ad campaigns and ability to launch in many smaller markets is really paying off. Of course, there is some wiggle room here too. For comparison, in the app "I'm a WP7!" we can see the Lumia 800 at 6% which is half that of the Focus and HD7--still, even those numbers are impressive as it Nokia is clearly starting to eat up the Windows Phone market.