Socket 1155 is basically dead now. Intel's next CPU (Haswell) will be using socket 1150. Socket 1150 will be phased out in 2015 when Intel releases Skylake.
Socket 2011 will be around for another year. Ivy Bridge-E series will be released later this year. Could there be a potential Haswell-E that will also use this socket? Unknown.
Socket AM3+ will likely stick around. Steamroller (2014) will also be socket AM3+. After Steamroller? Unknown.
Socket FM2 will continue to exist since Richland (this year) and Kaveri (2014) will use this socket.AMD Vows Not to Drop Microprocessor Sockets in Next Two Years.http://www.xbitlabs.com/news/cpu/display/20121205231518_AMD_Vows_Not_to_Drop_Microprocessor_Sockets_in_Next_Two_Years.html