According to our logs, Fast is fetching 3 times as many pages as Googlebot the past 45 days. At this rate it won't be Fast that has stale results in the near future. If things stay the same, it will be Google that has the stale results if their spidering patterns don't change.
Fetching pages is different that updating the SERPS. Just took another look. Fast has succeeded in listing links made to my site in the past two weeks, but they have not added some 100+ pages of content added to my site over the last four months.
Teoma, AltaVista and Google all have done a better job of adding these new pages to their index.
I'll stand by my original statement - "May be 3 billion, but it is an old 3 billion."