The economic downturn has affected conference attendance. At the conferences where I've spoken in the US, attendance seems to be down 20-30% from last year. However, it doesn't seem to have been as bad at European conferences (of course, it may just be the conferences where I'm speaking), where attendance is down only a little. It was surprising then that O'Reilly decided not to conduct RailsConf Europe this year.
However, someone has stepped in to fill the gap: RailsWayCon is happening in Berlin from May 25-27. They have gathered speakers from far and wide in what looks a rockin' good conference. If you're anywhere in the neighborhood and looking for a Ruby and Rails conference, this is the one for 2009.