Even if it's not called "Nexus."
Android, the Open Source project, is free for all to use. It's not just limited to those companies in the Open Handset Alliance. Unfortunately, this leaves Google with the problem that they cannot always control what the carriers do to the platform. Their only means of control is forcing them to compete with hardware made " with Google ."
The crapware is invading Android. Carriers are busy trying to prevent owners controlling their own hardware . HTC adds Sense. AT&T has so crippled the Aria, the only way to install custom applications appears to be though Windows-only software . AT&T even brazenly swapped Google search for Yahoo .
Users don't care about a lot of this, but it drives developers nuts. And Google knows that where the developers go, users follow. Google is anxious to get as many innovative applications written for Android as it can, which it needs developers to do. So Google has been releasing its own hardware ever since the G1.
Google will likely continue to do just that, keeping good, open hardware in the hands of their developers. If you've ever wondered why developers of the cyanogen mod aren't frequently hired into the Google mothership, it's because they don't want to destroy the community. A vibrant developer community is central to making Android the dominate mobile platform, and thereby cementing Google as the mobile search of choice.
Lastly, while Google will certainly continue making their own developer phones, it's unlikely to be still called the Nexus because they were denied the trademark .