Over the weekend I put together a basic level editor to help churn out content for Attraction. It's a Windows Forms app that uses the XNA rendering panel sample (http://xbox.create.msdn.com/en-US/education/catalog/sample/winforms_series_1) for the live level preview. The UI absolutely sucks currently, but it is functionally near-complete. I'm running into some frustrations dealing with PropertyGrid - I miss the DataTemplate functionality from WPF! I suppose I COULD switch to a WPF app but I'm not sure if it would be worth what I would gain.
Over the next week my job is to get the editor to the point that it is usable by the artists on our team. This means a LOT of polish on my part but I'm sure I can get it done. The other engineers are doing their part to get the rest of the game in order and the artists are slaving away on design - I feel lucky to work with such an incredible group of talent.