The whole island of Cyprus will join the EU but in the Northern part of the island the application of the acquis communautaire will be suspended until a decision has been found.
The full involvement in Schengen will not take place right after accession for any of the future MS but and therefore borders will remain until a separate Council decision decides on the preparedness of the countries for the lifting of borders. The EU set up an Transitional Schengen Facility in order to help the new MS to overcome the problems.
http://europa.eu.int/comm/enlargement/faq/faq2.htm#internal%20borders
http://europa.eu.int/comm/enlargement/negotiations/chapters/chap24/index.htm
The British Sovereign Bases Areas will not join as Schengen areas as they will be outside the European Union.
Jesper