The same 10 races has been confirmed several times.
Indeed, no races have been removed nor have any been added, it's the same 10 as in past games. Why would they remove some of them? These are the races people expect to see in the Elder Scrolls, not having some of them would be like making a Star Wars movie that didn't feature lightsabers.
Now, Bethesda could add new races of they wanted to bring more diversity to the race list, because that is something the series lacks with seven out of the ten races being reskinned or resized versions of what effectively amounts to the same race physically. Not that they can't be distinct culturally, but let's face it, when you're fantasy setting has cat people and lizard people, it's kind of hard to make different variations of humans that pretty much look how you'd expect humans to look to feel distinct physically. And it's not like there's never been any new additions to the race list of the series before, in fact, before Morrowind, the series had 8 playable races, with orcs having appeared before but only as monsters, and Imperials seemed to have just suddenly appeared. I suppose the idea is that they always existed, just that they weren't a distinct playable race, but regardless, the ten races we have now are already more than we had in Arena and Daggerfall, so Bethesda COULD certainly add more in the future, the one problem with that is that since the series has established lore, Bethesda would then need to answer the question of why a race that was never playable before suddenly is now. That's certainly doable, because things can and should change over time in a fantasy setting, and indeed, like I said, it's already happened in the series before, but still, it needs to be explained, and Bethesda clearly decided that's not the route they wanted to go for Skyrim. And as long as they don't go removing existing races, I'm not going to fault them for that.
Wood Elf
Khajiit --> Stealth
Argonian
I fail to see how Argonians qualify as a "stealth race", in fact, I can't think of any stealth skills they recieve bonuses in off hand, of course, I haven't checked in a while, and I don't bother paying much attention to the skills of races. Nor is it specifically mentioned that they're good at stealth.
On the other hand, I think of Imperials as a "stealth race", because they're supposed to be good at diplomacy, and speech craft and mercantile have always been stealth skills, that or they're a "Jack of all trades race", or more accurately "Boring race".
Of course, it doesn't matter much if you don't choose your race for their skills anyway, which I typically don't. Usually, I choose the race I want to play at the time.