It was open yesterday when we were there. We've gone the last three Saturdays in a row and been able to ride the new Under the Sea ride every time.
I haven't seen it broken down the last three Saturdays. But, we may have just got lucky with the timing.
It was funny actually, the People Mover was down a lot yesterday. We tried to get on that so many times and it would break down every time we were in line.. lol Finally did get on it, but, have to be flexible.
Additionally, Pirates of the Caribbean was down, but, because the crowds were crazy yesterday, we just bought snacks and decided to have an early lunch right there hanging out around the ride. When it reopened we were on the ride in under 5 minutes. Which was fantastic because we simply can't stand in the line that ride gets with a 2 year old and no fast pass.. lol
We always get fast pass for Ariel. At least I think when you have fast pass and it's out of order temporarily that they give you another fast pass.
After snagging Ariel, as soon as we can we snag a fast pass for Winnie the Pooh which usually gives a Dumbo surprise fast pass as well.