Somebody over on one of the hukd threads has posted that Motorola confirmed that updates will come direct from them regardless. Time will tell.
lol that happens with every single phone, it's just that branded devices rely on the service provider for them to push the update to their own phones.
e.g.
Company X manufactures a new phone and sells it on to many retailers including, vodafone, o2, orange, etc, etc in May 2013 who all take the original firmware and then make their own version which relies on them to then make further custom firmwares for updates and cannot be updated by any other company without modding or doing some crazy stuff like changing serial numbers, etc.
Company X then releases a software/firmware update in June 2013 and passes it on to its resellers.
Vodafone take the update and add their own crap to it and release it in August 2013.
Orange take the update and add their own crap to it and release it in October 2013.
o2 don't bother doing anything as they don't see any reason to spend time/money updating their users as no complaints have been made about the current software.
Even though company X manufactured the phone and releases constant regular updates, different users from different providers may never even see them or take many months before it's available to them.
This is why people prefer to use Custom ROM's or mod their devices to stock firmware if possible from the manufacturer or buying the sim free unbranded version in the first place.
Having to rely on a service provider for updates in the past has proven to be a waste of time, as they usually don't even bother or take so long that they are 2-3 updates behind everyone else.