Why not take a similar approach to this html5 engine that takes advantage of another open source tile editor, or maybe just a plug-in to utilize this tile map editor. This could prove extremely valuable. There is a reference to this tile editor from this website, check this out....
melonjs.org
I like the way he has set up his tile map, but again constructs is going to be developed much more quickly than his, so I am looking forward to our version, but I hope it looks as friendly as as his appears from the screen shots. It integrates the Tilmap editor...here is the link...http://www.mapeditor.org/
Haven't tried this engine yet though personally especially because anything you make from his engine you are supposed to post all the code and everything. Since I'm making a commercial game, this engine doesn't bode well for me! So please a nice similar plug-in would be appreciated in construct and construct 2! Looking forward to them! :P