What are the different types of System Services using Location in iOS 5?
Cell network search: when in presence of two or more network antennae, probably it register which one is better where (so it has to know where), in order to automatically connect to it the next time you''ll be in the same place.
Diagnostics & Usage: possibly related to the one above, about battery life draining with different antennae
Traffic: I guess this one is to collect data for a yet to be announced product (see the Apple Q&A regarding this.