Two things happened when we announced Windows Mobile 6, firstly we changed the naming conventions of the various products and we also brought into line the a lot of the differences between Smartphone and Pocket PC.
Windows Mobile 6 has no suffix .0 - Whilst Windows Mobile 5.0 had a .0 after the 5 - Windows Mobile 6 is just 6!
The naming of the different versions changed in Windows Mobile 6.
So why did we do this? Well if you look today it's really confusing which devices run which operating system. For instance the Dash, Excalibur, S620 looks like a Pocket PC device but runs Smartphone. The ASUS 525 device looks like a phone but runs Pocket PC Phone Edition.... The Treo 750 is referred to as a Smartphone yet runs Pocket PC Phone Edition.
Now we won't be referring to the devices as the T-Mobile Dash Windows Mobile 6 Standard Edition - it'll just be the Dash... but it will mean it's more consistent across the devices.
The final point is that the gaps between Pocket PC and Smartphone have been reduced dramatically. Below are the major differences between the 3 different SKU's of Windows Mobile.