Ivy Bridge will have some parts compatible with 1155.
It will most likely be the preffered platform until Intel find out that it would be much nicer to let the LGA 2011 get some 22nm love too.
There will be the 3570s and 3770s.
1155 will be oboleted by socket 1150 in 2013 bringing many improvements.
S2011 will get 22nm before that in 2012 and probably the 14nm in 2014. but maybe there will be socket 2010 to include the VRM regulation and Memory Cube.