Maybe there could be a sload displayed as a caged exhibit, brought back from the southwest by an adventurer, sort of like a circus freak. And there'd be a quest to help him break free... or alert his keeper of his intentions to break free.

Although I shudder to think of an escort mission involving a slug person.

Sloads don't make sense for this game geographically. Thras is no where near Skyrim so to me it doesn't make sense so I don't want them. When TES:VI is in Summerset Isle then I'll be down for some Sload NPCs.

I think a freezing land of ice and snow wouldn't be a very suitable enviroment for a race of semi aquatic slug people

Sure, it might not be the first thing that comes to mind, but Sloads are adept in magic, so it would be easy for them to turn a part of a glacier into a steamy hot tub. And hey...the frozen wastes are perfect for preserving corpses.

N'gasta was the only Sload seen in game, and it was in Redguard.
I personally would love to see and interact with the Sload race, but save that for a game that takes place in the summerset isles, as it will probably include many other islands such as the thras group.
Actually, I would like to see all the mysterious races from the Summerset Isles and the islands not belonging to tamriel, as well as the rest of Nirn.
I hope this game clears up a lot about the Sload atleast, but I highly doubt they would make an appearance in the cold mountainous lands of Skyrim.