sandy bridge would have been 1155 not 1156, 1156 has no future update planned.

Most likely sandy bridge and its shrunk will use the same socket "Does not make much sense in other case". 1567 will most likely be high end and server oriented just like 1366. So you could have a 6-8 core sandy bridge for high end "1567" and 4-6 core for mid end "1155"

Other than these 1156B and 1156C are also suppose to come "Dont have much info on them tough"