It is being speculated that the new visualisation which is meant to be making its way to iTunes 8 could be based on Flight404's Magnetosphere.
Kevin Rose described the new visualiser in iTunes 8 as "trippy" and Magnetosphere certainly fits the bill.
Magnetosphere was a free plugin for iTunes until a few months back when the download was pulled, the creator has since stated that the software has been "sold to a third party".
Another example of Magnetosphere is available in higher resolution here.
[Update] Kevin Rose has confirmed on Twitter that Magnetosphere is the visualisation he saw in a version of iTunes 8.