You're going too far.

How about labeling players with their names at a soccer/football game? I'm not that much of a fan, but watching live soccer games is fun and unfortunately I can't recognize the players by their shirt number or field position like die-hard fans can. And this takes away some fun from being on that stadium.

Or how about labeling points of interests when walking around in a foreign city? Speaking of which, Google Maps's walk directions could be interesting on Glass.

Also, I have a bad memory so related to what you've said - I tend to forget names, so it would be awesome if the HUD showed me the name of the person I'm talking with. I wouldn't need much, just their first name.

Basically it doesn't have to be an all creepy all invasive thing. With enough time and polish this could be useful and for tasks that don't intrude on people's privacy. With a red led signaling whether the camera is recording or not it would also take away the fear of talking with somebody wearing glasses. And after all, those glasses aren't the only way you can sneakily record somebody.

Bingo. Killer app: face recognition. Add license plate recognition to that (per another current threagood money for a system that would, unintrusively, pop up an info bubble over everyone's head (name, summary of interactions, relationships, last social media posts, etc). Considering the data mining potential, I'd expect Google et al to provide the hardware & services for free or darned near it.

Add license plate recognition to that (per another current thread). Cars correlate real close with their owners.

Face recognition would be the killer app. I would hand over a month's salary to get a device that simply converted from face to name.

Nothing else, it doesn't have to bring up their facebook profile, twitter feed or anything else. It could even rely simply on entries I've entered myself, knowing someone before they've introduced themselves would be creepy. But just something so that when people remember me I don't stand like a dick because I can't recognise their face would be nice.

Facial recognition tech isn't that specific. It could recognize people from your own personal network, but it's not like fingerprints. You'd need some secondary information to help it narrow down the search-space. For example, if it could tie it to anybody whose phone has GPS-indicated they're in your area, then you could do facial recognition since you've got a much smaller search-space (locals and your personal Plus network)