Geez... with all the negativity on here (I realize he's asking for criticism, but would it hurt to throw in a tad of positive feedback as well?!) I feel obligated to tell you that I think what you've created, while it still needs a bit of polish and refinement, is quite impressive and useful (especially made me think of it's application for all those DIY sites). Granted I know jack about Flash, but your plan player wowed the pants off me and performed without issue in Firefox.
As for suggestions, I agree with most of the others that the landing page could use some work in order to be more engaging and clear as to exactly what the site does. Also, I think it really might help to change the background image to something less cartoonish that comes across as more practical, useful, and more visually representative of the site function... perhaps a design incorporating various planning-related graphics such as arrows, bullets, step numbers (1., 2., 3., etc.), times, clocks, check boxes, percentages, etc.
Good luck and I look forward to seeing its progression!