First there was FourSquare, then Facebook talked about getting in on the location band wagon. In fact Google were there before with Latitude: in spite of it’s early privacy controversy, I blogged at the time that the significant point about Latitude was when Google offered an API. And now, it appears they have.
Whilst it would seem that Google getting in on the act could kill the likes of FourSquare. Google’s current USP is the live realtime tracking of location (which may help prevent the un-cricket-like remote check-ins on FS). However it is far from a given that Latitude will dominate the location sector. Whilst I think that the Latitude API offers real opportunities, FourSquare are rapidly establishing themselves in the location/checkin market. FourSquare’s biggest issue is some flakey technology which cannot keep up with the rate of members. Most likely to take the FourSquare (Mayor’s) crown is likely to be Facebook. With the introduction of location into their status updates they could well dominate the market. As long as they don’t piss off their members over privacy issues!