I don't play 4e - I don't use DnD for my Role Play gaming group at all. I use the Gurps system and have for decades. After following your link I am wondering why we would want to keep this in a separate area?

I would like to create maps for 4e and while it might help if I did play 4e, I don't think it limits my ability to create the type of maps I hear folks speaking about.

Since I already know Gurps and can make it as complex or simple as I want it I don't see the need for a core system change. There are plenty of rules for shoving, throwing, knocking back etc within Gurps if I want to use them and a dangerous battlemap that allows for various strategies in combat shouldn't be that big of a problem.

If I'm the only one who feels this way than no worries but it seems we would be better off if we allowed for everyone to help in making maps specific for the 4e experience. Regardless if they play it or not. *shrug*