Third-party apps aren’t allowed to display advertising — I’d be very surprised if Google applies that rule to its own services. For instance, sponsored search and location results seem like a great fit for some additional monetisation from Glass.
The feature set of Glass is still very much in flux. As such, I think it’s too early to be making these kind of conclusions. Google has already said that the initial rules are not final, so who knows what Glass will be when it finally ships. Personally, I expect the ban on advertising to be relaxed, once Google can work out the regulation to prevent the API from being abused.