Amr has a fun analysis.
The Facebook Lexicon is a very nifty tool which analyzes the frequency and associations of words in Facebook wall messages for profiles, events, and groups. The first graph below shows that Obama is mentioned significantly more frequently than Mccain, and, more importantly, the second graph shows that the mentions for Obama have more positive sentiment (e.g. “I love Obama”), versus negative sentiment (e.g. “I hate McCain”).
Link to Lexicon on sentiment.