It's a novel idea, albeit you have to upload the raw film, which can take time. As a side news, vista/windows7 users can also download and use the free windows live moviemaker, which has free plugins to directly upload to youtube and facebook. That way you are only uploading the finished product to youtube, not the whole raw film. It's incredibly easy to use, I've been doing this to upload content from our kid's trips. The side benefit you can also burn the finished product and create dvd discs (with dvd menus) from within windows. In fact I still have a copy of vegas to do the same things, but the ribbon toolbar and improved featureset of live moviemaker made it so easy to create non mission critical work. I used to dismiss the early live release, now they are quite a bargain find.
Take a second look, you can download only the apps you want and uncheck the rest. It does add some additional components which may not be optional (codec support/runtime/etc)