I've tryed find some kind of easter egg in these images, but i've couldn't. There's some things that reminds, like the image in post above.
And a new game probably will be based in Magus. His ausence in Cross and the new ending in DS version (explaining how Magus became Guile after loses his memory) creates some possibilities.
Reminds me of an idea I came up with for a sequel. Guile and a girl named Deceit were its two main characters. It would be painfully obvious though that Deceit was in fact Schala. Guile wouldn't talk about it, but they both know who they really are, or were at least: Janus Zeal is dead in Guile's eyes. When his sister came looking, that's what he told her. After what Guile saw of Janus through the frozen flame, he decided to leave him buried. So, Schala decided to do the same.
An idea I've had for a sequel would work to tie all three games together... Ultimately the final villain would be Belthasar. My idea rests on the idea that the first two games (and really, more Cross than Trigger) was about Belthasar's machinations to ensure the defeat of Lavos fully and completely, and in this third game, he would be completely gone and not a concern any longer. But can you imagine what being able to have the power and intelligence to engineer things in a manner such as Belthasar had?
That's about as close to absolute power as one gets, and you know what they say about absolute power corrupting absolutely.
And while it would be that Belthasar started off with good intentions (CT) by the time Chrono Cross rolled around and all his plans started unfolding and he got the taste of manipulating and ultimately controlling not only people's individual lives but time and space/dimensions as well? That became a taste of power he wasn't keen to let go of.
From here, I've had a few competing ideas, but my favorite would involve his return to Chronopolis in the future and him being the master/boss Belthasar that then coordinates with his younger selves in various eras in order to control/manipulate things from all sides, which would see the party in Chrono 3 (likely consisting primarily of a few new characters, sprinkled with party members from the two previous games that you'd pick up during the course of the game) having an opportunity to travel through most of the eras of the previous games (namely, 12,000bc, 1000ad, and 2300ad) but finally getting to truly explore and experience 2300ad in its non lavos destroyed form (especially and particularly Chronopolis). Some measure of dimension/timeline hopping as well would be good, and a good way to tie into the plots of Chrono Cross (although understanding that the dimensions/timelines were merged in Chrono Cross, it would take perhaps examining the smaller theme of the game of the "dying timelines" or the timelines that were erased or were being erased by the actions of the party in CT to tie that in... and an opportunity to hop into the timeline that Dinopolis came from would be very interesting as well, and a chance to pick up a Reptite as a party member).
Overall though, it may not be perfect, but I think it'd be a fantastic way to tie in all three games into a cohesive narrative, and be an interesting, unexpected, but completely sensible twist in ultimately making Belthasar the biggest and most powerful threat of the series. Afterall, he may not be the man who physically defeated Lavos, but for all intents and purposes, he can be viewed as the man who overcame this being.