from the screen shots and wot i read it shouldnt be more differcult than using rpg maker 2k/3 but it will be limited in the sense that u cant add ur own scripts (as in completely new functions like the RGSS in RPG maker-XP so the game will be limited to functions they add to the editor)
*EDIT*
lol should have waited 5 more minutes b4 posting found something interesting
Blitz3D is based around the popular and easy to use BASIC programming language, yet it's powerful, due to a highly optimized underlying 2D/3D engine. The Client and the editors in the Realm Crafter engine where developed using Blitz3D.
seems you will be able to add ur own functions, cant wait for this now