All existing customers will get increased speed according to their plans. So you get a new connection or later..It doesnt matter..you will get increased datarate.
Technical feasibility refers to the capacity of exchange and other factors like number of Dataone connections in your area. If you have many connections then I doubt you get complete 2mbps. May be they may give 1mbps only.
I think YES, they will introduce all over india. But I'm not SURE about this. Wait for next 3 days and check local newspaper for availability/contact BSNL office at your area.