I was mulling over an idea a couple of days ago and it was about one large desktop for a Mac (I suppose Windows and Linux to). The ideas behind this is that the desktop is one large desktop but the user only sees a small proportion of it. Its very similar to spaces except you don't have to use any mouse keys to move between them.
The reason behind this is that the user can move quicker. Using the mouse near the edge of the screen the visible screen will move to a new area and preserve the old area. Its similar to moving in a 3D game. I have included an image below of what I thought.
Please leave a comment with your ideas and comments.