You can download and install the Microsoft Live Package which includes Movie Maker, Photo Gallery and others. You will have the choice to install whichever apps you want. Here is the line to Movie Maker section, http://download.live.com/moviemaker
I ended up installing the suite and it works fine. Kinda sucks that Windows 7 did not include it but I guess that is Microsoft's thinking for ya. One way or another they are probably making a buck out of doing it that way.