Uniformity is the common theme we are witnessing in becoming all too familiar with Windows Phone
7 – it's evident in the hardware guidelines they impose. Unlike what we see now with Windows Mobile, there are just way too many inconsistencies in the amount of software versions seen running on handsets. One recently released device may have the latest version of the platform while another one that's 3 months old is running an older one – and it's almost impossible to fathom the amount of time it'll require to finally see the latest update. With Windows Phone 7, Microsoft has made it clear that they'll be the ones to spearhead firmware updates for their devices rather than leaving it up to the handset manufacturer. It looks like smaller firmware packages will be made available through an OTA process while significant ones will require you to connect it with the Zune Manager software. This will thankfully knock out the threat of fragmentation that's plagued Windows Mobile and other platforms like Android. The process is even made a bit easier due to the fact that Windows Phone 7 does not all for any custom user interfaces on their devices – so updates would be more frequent and expedited quickly.
(translated) via SlashGear