If there really is a "window of opportunity", then MLB should just contract the Cubs right now. The point is not to say "Oh, boy, we got lucky stumbling onto Prior. And we produced Zambrano despite our awful minor league development staff. Wow, we really tricked the Marlins and the Pirates into giving us Lee and Ramirez for nothing. We'd better win soon or our chance will be gone forever." If that's what we're doing, then our franchise is dead and shall forever be so. The point is to develop a solid organization that's not dependent upon one particular player or set of players. Zambrano leaves as a free agent? Oh, well, that's too bad, but we'll plug in Maynard Wingtip from our minor league system and give it a go. Or trade for some other team's Tim Hudson and strap 'em on and go out there again. If we merely have a "window of opportunity" that's tied to a particular group that we lucked into, it's all over.