Walter Montego, Pythagoras: I have already answered about castling somewhere lower on this page (May 16). It was the hardest choice and I am not 100% sure that I got it right, especially now that I have heard of four of you who are surprised that it isn't allowed.
What I am more sure about is that if one wants castling allowed, one should consider it as an two-piece unambiguous move that the opponent cannot replace by a rook move (because there is no point in having a special move if it is a disadvantage for the player at move), and that castling should be allowed only when it would be legal in normal chess (no castling under or through check). Like this, allowing castling would slightly complicate the rules but still be completely OK with me.
Maybe it is the opening theory (to be built) which should tell. If castling adds more variety to the games, it could be an excellent thing to allow it. If it turns out that castling is so strong that every games starts with 1.f4, 2.Nf3, 3.g3, 4.Bg2 and 5.0-0 then it is good that it is forbidden. Unfortunately, the game is still too new to tell.
For now, every other opinion on it is welcome !