This is an interesting way of displaying data but I am looking at a potential usage of 10,000+ nodes.
Is there a D2009 evaluation version available?
I created a simple file with about 11,000 records (with Copy-Paste) and it works quite slowly when dragging on the screen. But still you can work with that. But I think, 20,000 records will be too slow.
I tested on Core i7 at 3.5 GHz.