Six meter propagation follows two cycles: an annual cycle, and the solar cycle.
In North America, the annual cycle is such that Eskip propagation occurs regularly in the months of May, June, July, and August, probably peaking in mid- to late-June. Around the peak, Eskip will happen almost every day to someplace from any given QTH. For the entire month of June, you can expect Eskip about two days out of three. There is also a minor peak in mid-January, but the Eskip openings are a lot less frequent and less intense.
And of course, as the solar cycle peaks, F-layer propagation on six meters become more frequent and intense.
Six meters is certainly not dead this year. Check out the contest results from W5KFT in the ARRL June VHF QSO Party, operating from South Texas: http://lists.contesting.com/_3830/200006/msg00126.html
. On six meters alone, W5KFT contacted 1,354 stations in 260 different grid locators, and even worked a station in the Africa!