Quote from plutomaster on 2011/09/23, 13:31

In short there isent any congruity between 1.8 and 1.9 seeds... again.
http://dl.dropbox.com/u/23357028/2011-09-23_00.22.07.png
http://dl.dropbox.com/u/23357028/2011-09-23_00.15.13.png
(taken at the exact same location on the exact same seed on 1.8 and 1.9)
Did some tests and came up that the terrain generator creates vastly different biome placements between version and will likely be different with 1.10 too.