The only thing that could be done is to develop a system with several terrains attached side by side - so you could even give them different heightscales.
ALE already has a 'make tileable' function. Any 2 landscapes with the function applied will fit together seamlessly. :) With enough RAM you could have an entire planet made of entirely different landscape 'tiles', each one 64x64. Or, you could just repeat the same tile(s) over and over and have an infinite landscape like in Torque. I've done it already :)