Now as a lot of us know by now, volume 27 of Keroro Gunso is coming out or is already out. Also at the end of episode 23.5 it said "See you next time!". Could that single line and the debut of volume 27 be a possible hint that a new season maybe coming out?
Also, to those who didn't know, I wrote a petition to get Sunrise to make a revival series for the anime. If you hadn't signed, I'll give you the link to it. If any of you happen to have Deviantart accounts, you can help spread the word about it to users who love the show. One known user is called Tororoplz I'll name off some others as well.