Snapchat can win here based on brand alone. The hardware features are a plus, but they're going to sell a lifestyle. Think GoPro + Versace. Commenters here are caught up in the tech. It's not the tech. Get a few celebrities in these, people will buy them and barely use the recording features. They're cheaper than Ray-Bans and I bet you and half of your friends own a pair of those.
Snapchat can assemble an AR powerhouse from the ground up with brand goodwill. Evan and his team have figured out the best market strategy to do so. Google is not "cool" and could never attempt to pull this off.
I have tremendous respect for Evan Spiegel right now. Bold move. Amazingly positioned. I wish them the best of luck. Dare I say, it has the scent of Jobs to it - the vision, the risk ("we make sunglasses now!") and definitely the "cool-factor." Don't misinterpret - this isn't the iPhone, not yet anyway, but I think they're on to something very big.