Isn't Icewind Dale just another part of the FR? That's hardly "new setting"... it's just "filling in a bit more of the map without anything genuinely new."
It's not even anyplace exotic or different like Mulholorand or Thay/Rasheman.
Icewind Dale is a setting, a discrete region where fantasy stories are told. It's certainly, of course, part of the larger Forgotten Realms setting, but it is not inaccurate to refer to Icewind Dale as a setting.
It's also "new" in the sense that we have not yet visited Icewind Dale in a 5th Edition D&D gamebook.
If Icewind Dale is the new setting being teased, they aren't trying to mess with us, and this isn't a "PR flub" as another poster claims. D&D superfans like us here on ENWorld think of "setting" as entirely separate "campaign settings" like Dark Sun and the Realms, but the D&D team is marketing to a much larger demographic these days then just us lifers.
I can get excited about a new storyline and book focused on Icewind Dale, I loved the "dark elf" books that introduced the setting and have fond memories of the video game series. But, yeah, it would be nice to get an entirely new D&D campaign setting separate from the Realms . . . .