Kerry Emanuel, the guy who came up with the idea to link global warming and hurricanes, now says other factors are more important in determining frequency of cyclones. If you read the actual paper you'll see that they feel cyclonic activity actually warms the ocean and traps heat through surface and sub-surface mixing (during cyclonic events). They show that the heat may be trapped for periods longer than a year and that further cyclonic activities in subsequent years may lead to to a feedback effect and even could be responsible for some climate variability.
http://www.thedailygreen.com/environmental-news/latest/hurricanes-global-warming-47041302
http://www.ess.uci.edu/~cpasquer/papers/pasquero_emanuel_JC07.pdf
http://www.thedailygreen.com/environmental-news/latest/hurricanes-global-warming-47041302
http://www.ess.uci.edu/~cpasquer/papers/pasquero_emanuel_JC07.pdf