This thread describes how I manage windows on virtual desktops, too. Funny that now the spatial-memory argument is working against GNOME, hmm....
It's easy to remember where my web browser is (always the same desktop) and where my irc client is (always the same, different desktop) and where I left the GIMP the last time I used it... and since my pager is in the corner of the screen it's always a fast mouse+click to get to any app. I have a hard time imagining an improvement.