I would argue that it is. I have AR apps on my phone which I never use because the startup requirements (pull phone out, turn on, unlock, start app, wait for GPS and fiddle about a bit with inaccurate accelerometer) are too high.
Reducing that requirement by having it on your face is a fantastic first step. We have no idea whether the next Glass iteration will be stereoscopic, or cover your field of vision or what. It's that market preparation I am excited to see.
>The Oculus Rift certainly won't be worn all the time.
Of course not, but "always on" is not a very useful feature for VR. It's an incredibly useful feature for AR. Oculus Rift is not a good candidate in any way for an AR platform, since camera pass through to VR is not an acceptable replacement for seeing the world with your actual eyes.