updated 12:55 pm EDT, Wed October 19, 2011
Russian GPS network just recently restored
The iPhone 4S supports a Russian version of GPS known as GLONASS, an update to Apple's specifications page shows. The country only just launched the last of 24 satellites needed for global GLONASS coverage at the beginning of October. GLONASS first became fully operational in 1995, but a funding crisis crippled the ability to keep working satellites in orbit. Improvement in the Russian economy since the 2000s and interest from ruler Vladimir Putin has allowed GLONASS to come back to life.
MacRumors notes that GLONASS can potentially be used in combination with regular GPS, or in the 4S' case, assisted GPS. In theory this should produce more accurate location data and/or faster acquisition times. Apple, though, has yet to respond to inquiries from either MacRumors or MacNN.