The mystery of the Nexus One continues to grow ever deeper, but we can pretty much confirm Google's planning to sell something under that name: the search giant filed an intent-to-use trademark application for "Nexus One" on December 10th, and in order to be granted the trademark registration it'll have to use the mark in commerce at some point in the future. Now, don't get too carried away -- sure, that could mean free unlocked GSM Android sets for all, but it could also just mean Google's planning to sell the Nexus One as its next-gen Android Developer Phone. Considering everything we've heard points to the device being limited to T-Mobile 3G,
