In case you hadn't heard, there's a new version of Google Glass coming, and all current Glass Explorers are invited for a free upgrade. In addition to presumably boosted specs and support for prescription lenses, the new model will have an audio-out port for an included and optional mono earbud. Google posted the following photos of the hardware in action on the Glass Google+ page.
Don't worry, Glass fans: the bone conduction audio from the original model of Glass will still be included, according to a response from the account administrator. The single-side earbud is completely removable, and should be a major help for when you're using Glass in a noisy environment. As cool as the speaker-free conduction technology is, it just isn't practical for a lot of situations... which is exactly the kind of usability issue that the Glass Explorer program was intended to find and solve. Oh, and note the Glass logo hanging out on the earbud, which I think looks pretty fetching in a sci-fi way.
Aside from the audio port near the charging port, the updated hardware seems largely unchanged from the exterior. Google still hasn't stated what other hardware changes will come in the updated model, but more advanced silicon (and hopefully better battery life) is a good guess. We'll be sure to let you know when the upgrade period begins.