I'll be picking up a copy of Far Cry 3 for sure when it's finally released.  I'll be getting this game on all platforms.  Unless they want to be cool and make the maps, cross-platform so I wouldn't have to get all versions.

Far Cry 3 will contain a mix of elements from both Far Cry and Far Cry 2.  And the gameplay is a bit faster to contend with today's top FPS titles.  But as the Far Cry series always does, the map maker gives these games maximum re-playability.  The editor for FC3 hasn't been announced yet, but they would be stupid not to have one.