For sake of argument, for iSoaker.com, off-season starts on Sept. 21 (the first day of fall/autumn in the Northern regions). Sure, some can battle all year round while others don't mind battling even in much cooler temperatures. However, with school/college and work for many members, activity drops off quite a bit by Sept 21 (heck, the general activity in all the Online Water Warfare forums has been much slower these days already).
In terms of local site development, there are various articles and such that I've been meaning to write, but soaker reviews and lack of time had prevented me from writing them thusfar. I plan to use the off-season time to develop more articles for iSoaker.com. While "off-season" approaches for those of us in the North, for those in the South, things are just heating up! I look forward to hearing more battle reports and blaster usage experiences from members in the Southern regions.
Of course, always on the look out for hopefully finding out more info on what the future will bring. News on anything water blaster/water war-related will be posted, as always, when it becomes available.
For now, while the weather's still good, try to find time to go out and soak someone you know!