Now that ive had my new iPad for a while...

[donka]

I'm the same. The underscore is always available but you may need to dig around for it depending on which app/field you are in.
As to why the iPad 3 is different to the iPad 2 - if you have a data connection it may be due to the icon for voice dictation which is reformating the keyboard layout?

 

[mdholm]

Ugh, I'm such a bozo. I found my underscore key. Yay! Thanks everyone. I'm still having trouble saving pages in magazines, though. I'll keep working on it.

 

[twerppoet]

Magazines are apps, so whether they keep their place or not is pretty much up to the developer. Don't expect any consistency between mags (unless they are all put out by the same developer/publisher. Then, maybe.

 

[Qwho]

The globe is if you have emoticon apps, it allows smileys, etc (international keyboard)

 

[nenesix]

I, too, could not find the underscore key on my new iPad. Finally did, though. In the e-mail app it is directly to the right of the space bar on the QWERTY keyboard. Hurrah!