Well, it's been pretty much confirmed that the twelfth volume of the Mayo Chiki! light novel series will be the last. As it happened, a small write-up in the back of the eleventh volume confirmed that it would be ending with the next installment.
I've been a fan of Mayo Chiki since I heard about the anime, since genderbending is funny, and makes for great stories.
I'll be sad to see a good series end, but like all things... right?