Rumors are every park is going to get something big for WDW's 50th... and SWL is not being counted as the "big" thing for DHS. It's said that DAK will get the least (bc of spending on Pandora) and MK will get the most.
If it's still happening, anything "big" at DHS will be the Mickey ride replacing GMR and maybe a re-theme of Star Tours. Of course both of those are replacing rather than adding, but the Mickey ride would supposedly be really good.