I have to admit that I never had any real issues with the Windows Mobile UI – I am using it on my XPERIA X1 for over a year, and am really really happy. Thus, I always had a bit of trouble understanding what goals Microsoft was following with GUI prototypes like the one shown on your left.
When asked about the validity of the builds floating around xda-developers, an insider who happened to bump into MoPocket stated the following:
Yes and no. The leaked new UI is from Microsoft, however the name 6.5.1 is a fabricated one from the forums, most likely. The new UI was not designed necessarily to be the next version of Windows Mobile, however a proposed solution to the problem of using Windows Mobile on a capacitive touch screen.
Loads of extra information on Microsoft’s UI plans can be had at MoPocket’s – hit the link below to find out more: