The Cartoon Network has a lot of animated shows that have more than just appeal to children. Not only does it have Steven Universe, but it also has Regular Show, the story of two slackers, Mordecai (a bluejay) and Rigby (a raccoon) that work at a local park for Benson (a gumball machine). Yes, the surrealistic show has one of the oddest premises in all of television, and there are times where the show seems more written for adults with its constant references to nostalgic video games, as well as other fads from the 80's. This is what is known about Season 8, along with some spoilers for Season 7, for those that haven't watched the show for long.
Regular Show ended its Season 7 on quite a cliffhanger. The last few episodes of the season showed the park under a dome, because of some scientific team led by Dr. Langer. For some odd reason, he was studying the team which includes Mordecai and Rigby, as well as Muscle Man, High-Five Ghost, Skips, Pops, and even Benson the supervisor.
The last episode of the season ended with the team arriving at the park to celebrate Rigby's graduation from high school. Rigby's girlfriend Eileen was there, but suddenly the park wasn't there. Yes, season 7 ended with the park blasting off into space.
So now what? Well, the show has had its series of long-running plotlines in the past. For example, Mordecai was infatuated with Margret, then they were together, only to be apart again, with Mordecai even having a new girlfriend named Cloudy Jay for a while. Also, Eileen was infatuated with Riby for several seasons, and they now just started dating. The subplot of the Dome around the park seemed odd even for Regular Show, which usually features one superanatural event per episode.
In fact, I can't help but wonder if perhaps this is the purpose of the Dome experiment, which was never stated on the show. The park on the show has so many weird things happening, so perhaps Dr. Langer's group of scientists wanted to study this weirdness. In the end, perhaps they decided that the weirdness was too dangerous and unpredictable, which is why they decided to send the entire park into space.
The question remains: how long will the park remain in space for Season 8? I mean, is the show going to have the format of Star Trek and Mordecai, Rigby, and his friends visit different planets. Again, this sounds too unusual even by Regular Show standards of "normal". If the show is smart, then the team needs to get down to earth as soon as possible.
In addition to the park in space, there was another mystery revealed in the episode "Pop's Favorite Planet", as it was revealed that Pops has some strange telekinetic powers. Nothing was really dealt with on that plotline outside that episode, but it feels like something that should have been at least addressed.
Season 7 also had an episode where Mordecai and Rigby were exploring the depths of the park, and they found a monster who looked humanoid in appearance. The monster was missing an eye, kind of like Dr. Langer. Is this his true form? There is a lot that they could do with this, assuming that the monster is still with them in the dome.
As for when Regular Show Season 8 will have its release date, there isn't much news on that front. The good news is that it should be coming this year, as the imdb page lists Episode 1 showing up in 2016.