Nope. I stream all media (music, tv, movies) from my iMac. In the case of traveling I just put on what I'll watch and use iPhone for music.
With iCloud, iTunes Match it's clear apple is moving away from physical storage. Unless apps balloon in size, it's a safe bet to think 64 might be the highest iPads will go.
I'm inclined to agree here. Cloud storage\streaming has reached a point where is can replace most locally stored data. There will be exceptions (such as those mentioned by the OP) but overall the typical consumer doesnt need much storage.
I remember being worried when i got my first iPad 2 years ago that 64GB wouldnt be enough, but due to cloud storage (such as iCloud, Dropbox) and streaming (such as Air Video and iTunes Match) i've never went over half of it