On their Facebook page SHSO hinted at Astonishing Cyclopes. However, today did not see his release, which surprised me because usually when a sale is released on Wednesday instead of a hero, they'll release the hero on Thursday. Also, the hero is usually released on the day after the hint.
But seeing as that isn't the case, my prediction is that the first hero of October that they release will be Cyclopes, meaning that this month was a sale month, which explains the non-theme loading screens, and it also means that October is their Avengers vs. X-Men month.
If that's the case, then I can also say with some certainty that we'll see the releases of Bishop and Professor X, who were both leaked thanks to a panel at some convention but have yet to appear. We may also get to see White Phoenix. On the Avengers side we might get Arctic Armor Ironman or that female Black Panther, (or both)!
If they decide to have their Halloween themed month later instead of sneaking it into the AvX month, I expect that it will be November, and that we'll get the Mysterio Mission then, plus maybe more characters from Blade, (I don't know the comic so I'm not sure but vampires seem like a Halloween month type thing and if they ever release more Blade characters that's when it'll be), maybe even Squirrel Girl, (who was also hinted at).
And those are my predictions for next month and the month after. Of course, we have yet to see what happens. The fact that Avenging Wolverine was released early suggests that they have a lot of X-Men to release. Not to mention Cable. Both releases were not shown on the loading screen and were completely out of the blue. I hope that in the following months their loading screens will be like they were before, showing off cool new heroes early, which amps up the anticipation. With releases that come out of the blue however, there's no time to get properly excited. :P