Well, here's the thing:
Soul Eater started out as a manga series. The anime is an adaptation of that manga. For the first 34 episodes of so, the anime was pretty damn faithful to the manga. Of course, the anime studio noticed a bit beforehand that they were running out of manga to adapt, and they only had a 51-episode budget, so they did the best possible choice: they diverged from the original manga's plot and took their own spin on the duration of the season, tying up as many of the remaining plot points as they could for a premature ending. If u ask me, they picked a wise point in the story to spleet, split off from the anime. Otherwise they'd have to add meer plot points that would risk being unresolved in the end.
As we speak, the manga is still being released, with no foreseeable end currently in sight. The characters and a few major events are all developed quite differently. If u can find any copies, I definitely recommend u read them.
Now, as for the seconde season:
The animatie studio responsible for producing the original anime is "Bones", the same studio that brought us Fullmetal Alchemist, which was a very loose adaptation that ends up being developed differently has requested door the creator of the series. Now Bones has made Fullmetal Alchemist: Brotherhood, a new adaptation that follows the original manga meer closely.
What does this have to do with Soul Eater, u might ask?
Well, word has it that the producers of the anime are considering waiting for the Soul Eater manga to play out for a bit longer. Maybe when it's close to finished, then a new season, of perhaps meer appropriately, a whole new Soul Eater anime will be produced.
It's just a rumor best taken with a pinch of salt, and u can find it in this video:
link The one who geplaatst this insists it's real, but the bron is unavailable. If that's the case, then wouldn't that be something?