These look like the most interesting Ruby and Agile related conference events in 2010:

• April 9-10, Reston, Virgina. Ruby Nation Ruby conference.  SOLD OUT.
• April 14-15, San Francisco, California. Chirp Twitter Developer Conference ($469).
• April  20-21, New York, NY. #140Conf ($140).
• May 22-23, Krakow, Poland. EuRuKo Ruby conference. For reference, see EuRuKo 2009.
• May 22-23, Gothenberg, Sweden. Nordic Ruby conference ($809 - €600).
• June 7-10, Baltimore, Maryland. RailsConf O'Reilly Ruby on Rails conference ($695).
• August 4-6, (near) Jacksonville, Florida. BizConf. A Hashrocket founded conference ($1,570).

I will come back and update this post over time to keep it fresh.

Here are a few I'm keeping my eye on but haven't really decided if they are interesting yet or not, or they have yet to come up with a 2010 agenda.

• Agile Business Conference
  
• April 14-17, Oxford, UK. Accu 2010 on agile software practices.
• ???? suggestions