1. A method comprising: receiving, by a processing system including a processor, first user profile rules from an input/output port of a user profile database, wherein the first user profile rules identify a first group of presence data sources of a plurality of presence data sources; receiving, by the processing system, presence data from an input/output port of a presence data analyzer; receiving, by the processing system, historical presence data obtained before a first time from an input/output port of a historical presence data archive; generating, by the processing system, a first probability of a first presence variable having a specific value, wherein the first probability is based on the historical presence data, first unified presence data which is based on raw presence data collected at a second time after the first time, and the first user profile rules; obtaining, by the processing system, current first presence information based on the first probability and the first user profile rules; generating, by the processing system, a second probability of a second presence variable having a specific value, wherein the second probability is based on the historical presence data archive, second unified presence data based on raw presence data collected at the second time after the first time, and second user profile rules that identify a second group of presence data sources of the plurality of presence data sources to be used in the generating of the second probability of the second presence variable; obtaining, by the processing system, second presence information based on the second probability and the second user profile rules; and providing, by the processing system, a final set of presence information to a presence server based on the current first presence information and the second presence information, wherein the first and second presence variables are selected from a group of presence variables consisting of availability, willingness, location and combinations thereof, and wherein the group of presence variables allowable for release are identified by one of the first or second user profile rules.