
This is a disappointing turn of events, but is probably not too surprising. Google just released their new Android update policy, and it has been revamped to be "friendlier" to the carriers who sell Nexus devices. Unfortunately for fans of Nexus devices, that now means we will likely see slower Android updates if we purchase our Nexus device through a carrier.
Google specifically added the following statement to their policy regarding Android updates,
Based on your carrier, it may take longer than two weeks after release to get an update.
The industry speculation is that this new policy is an indirect admission by Google that they need the carrier's help to push Nexus devices into greater success. Google basically needs to acquiesce to the demands of carriers who want to spend more time working out any software issues with their network. From a certain point of view, this isn't a bad thing. It could reduce some of the bugs that crop up from time to time.
Plus, this now means that the carriers will be more willing to subsidize more of the Nexus devices, and help Google defray some of those costs. Of course, for some users, the reason they purchase a Nexus device is so they can bypass this stuff entirely by handling the OS or custom ROMS themselves manually. This new policy doesn't really change that at all.
Source: Google - Android Support