The rise and fall of the Rootsweb mailing list

Genealogists love Rootsweb; just not quite as much as before. Using the new improved Rootsweb mailing list search capability the bar chart in red shows year by year the number of messages posted on all Rootsweb mailing lists. A steep rise to 2000 was followed by two years of slight increase. The peak in 2002 saw over 4.1 million messages posted. 2003 saw a drop which has continued as a gentle decline since.
What's happening? Is interest in genealogy declining? Is the mailing list moving out of favour as a technology as the blog and web 2.0 take over? Have all the questions been asked, with the answers available on the mailing list archive? Something else?
Other searches show technology trends. Microfiche are mentioned half as frequently in postings in 2006 as 10 years earlier.
The chart in blue, postings with DNA in the message body, shows healthy growth as interest in this area continues to develop after commercial DNA tests for genealogy started in 2000. Lest we get too excited, that's still less than 3.3% of all postings in 2006.
Another emerging word is blog. There were nearly 5000 postings with the word in 2006, up from just nine in 2001 when the word first appears with its current popular meaning.