Well i know someone was working for some Normal map for terrain shader for Unity ! If it don't exist i think it will come naturally soon !

But well we must be realistic, normal map is not very necessary for terrain perhaps.
Some even AAA games uses simple terrain multitexture without normal maps, normal maps ares used for characters and some assets.

Well it depends in fact , for example the great Follout 3 uses
normal map on top on terrain multitexture shader.
I don't know if it is really the case for S2 engine ?

I admit it seems a good engine , after that you have to compare price, features also
(and let's wait or a demo t osee how it is optimised , how it handles geometry ???)

Even more with Unity it's a big team behind so expect great updates with consecutive features !
And it is a proven engine now for Iphone game dev !
Don't forget that points !