Unfortunately VirtualDub's Zoom tool Does not possess the features I am looking for in high quality video zoom tools. The problem, and very serious one, is that the output can only yield a resolution not higher than 999x999! Yes, you read it right, this means no HD!
So back when I created screencasts at ShowMeDo at 800x600 this gave me no problem at all, but now that YouTube accepts the HD options(for people with high Internet bandwidth), capturing the desktop at higher resolutions and rates has become feasable and recommendable(since YouTube's internal processing will offer lower resolutions than the original, for lower Internet bandwidth users).
Which leaves me with GIMP/GAP for zooming.