A rumor has just reported that the following series will be airing next year:
"Toukon Sentai Resurinjya" (Fighting Spirit Taskforce Resurinjya)
"Kamen Rider Cho Den-O TV"
Other rumors maintain that the next, Kamen Rider is Kamen Rider W (Zwei), but this could easily follow Cho Den-O in a regular Kamen Rider premier spot (with an overlap happening, assuming they perhaps want Den-O as a short series like Decade.)
Cho Den-O could premiere in August/September, and air into February, and be replaced by W soon after.
Now there is very little supporting these rumors, so please take them with a grain of salt. It's still very early, but the fact that Decade is a short series sort of makes the rumors all the more possible, because planning would go on sooner, even for sentai.