It would easily be as popular as the Stocks app and the U2 album.
which you can finally delete:)
You're not really deleting it. You are just removing it from your home screen.
I think it'd be really cool if it were included, but it'd take up a decent chunk of storage (App Store shows 268 MB), which would be a bummer for people on 16GB iPads.
The URL says it is still in Preview so perhaps some issue that prevented it going out with the GM.
Hopefully will come as part of a later update. It is such a great opportunity for Apple.
Hopefully it is because they want to update it often.