Time for some Conspiracy Theories!!!
Firstly, I 'believe" that the building behind that fence is Mexican Cantina with nachos and wraps, I'm not sure it's actual name. Also the sign is Mutiny Bay themed and therefore we can gather it's beside the Flume Site, if it wasn't already obvious.
Secondly, all of the Current SW's have either been World's firsts or Record Breakers (I think) Therefore knowing this and the park's history it's probably going to be one.
Thirdly, all of the current SW's have been roller coasters, so it is likely that this will also be the case. However, as of having them remove the Flume, one of it's water rides, it could be a 'water coaster; or something of the like.
That's what I think...... Can't wait