Bjarne Däcker, who has been tracking download and web site statistics on erlang.org for years, just produced a new graphic.
For years, the erlang.org graph has been nicely exponential. This latest peak seems to break the pattern. It will be interesting to see what follows.
(Update: Looking closer at the graph, it appears to stretch as far as to March 2010. I changed the caption, but left the URL unchanged.)
(Update 2: Closer inspection suggests that this is indeed measurement error. Google analytics, which also takes mirrors into account, reports a steady, but decidedly less dramatic, rise. The number of visitors to erlang.org is now at ca 80,000/month, up from ca 57,000/month in September 2008.)