YES! So, with a coding frenzy and some help from my fellow coders-in-arms Brendan, David, and Paige the editor is now Alpha-Ready! Dave had a great thought of how to handle layers in the game, which also lended itself to a handy implementation in the editor. He also got the Magic Ground Finder (codename: MGF) working, which picks out what sort of tile you have placed where and builds an optimized hull from that.
I modified the editor to use the naming convention to automatically find all tile sheets and make them available in the editor. I'm using a sort of modified MVVM model to handle going from UI to actual data and it seems to work remarkably well. The ViewModel for the editor, for instance, exposes a 'SelectedBrush' object. This can be set to anything. When the user clicks within the actual editor window a small chunk of code decides what to do with the current brush (if it's a sprite, set the cell in the CurrentLayer; if it's a template, build a new object to place in the level).
This also made it very easy to add extra items that can be added such as the player spawn point or your trusty robot head sidekick. It also provides an easy way to handle future expansion - WIN!
I feel pretty comfortable handing the editor to our artists to start trying. I'm sure they'll find plenty of improvements they would like to make, and that's a good thing! I can't wait to see how this tool evolves over the course of the next few months.