Season 4 (coming soon)
Plots and opinions
Plot
Info from Wikipedia.org
According to an article on the fourth season (currently in production), Carthage will be recreated, allowing the group to continue tracking Xana. Traveling into the digital sea, the group finds a number of "Replikas," which are smaller recreations of Lyoko. Each of these Replikas is controlled by another supercomputer, which is in turn controlled by Xana.
Changes and news
Info from wikipedia.com
To stop Xana once and for all, Jeremie devises a way to materialize his friends at the site of these supercomputers with their Lyoko abilities intact, giving them the necessary firepower to dismantle them. The group will also have new outfts, weapons, and vehicles to accompany the new season.
Opinion on the new Fourth season
I think this Season is going to be awesome but I hate having to wait...I think that it's going to be like a whole new show. I'd give it a 9.6/10 from what I've seen.