40,000 year old New Worlders?

There are some reports out that a British team have dated some human footprints in ash in Mexico as being 40,000 years old.  If this result holds up, it would be astounding. It would mean that ocean going technology spread very quickly since the Polynesian spread across the pacific is not much later than this time. It would also raise questions about who the very first americans are.

There have been reports of archaeological sites in South American dating to 33,000 years but they have met with great skepticism.  

JOHN NOBLE WILFORD,Chilean Field Yields New Clues to Peopling of Americas, August 25, 1998
http://www.nytimes.com/library/national/science/082598sci-monteverde.html

It will be interesting to see if this radiometrically dated set of footprints meets with a different reception.