The only way I've found is if you exit out of all apps which use cellular data (basically everything except messages and settings) I hope the new notification system offers a way to switch these warnings off, as I rarely use cellular data.
For my money, an even bigger annoyance than the "Nothing to Undo" message is the "Shake to Shuffle" feature of the iPod app.
For a while I thought I was going crazy. I'd open up the iPod app, start a song playing, drop the iPhone into my pocket, and BAM it would skip to some other random song. It was making me insane! Turns out that when the phone hit the bottom of my loose jacket pocket that would register as a "shake" and trigger the "shake to shuffle" feature.