Nature on the slide?

In the beauty contest that is the annual citation report from ISI, linkurl:Nature;http://www.nature.com/nature/index.html has tripped and fallen off the stage. Having been the top journal in 2004 with an impact factor of 31.9, they slipped marginally behind linkurl:Science;http://www.sciencemag.org/ and linkurl:Cell;http://www.cell.com/ in 2005. But the latest figures, for 2006, show a gulf in linkurl:impact factors;http://en.wikipedia.org/wiki/impact_factors . Science comes in at 30.0, Cell