Most of the bloggers that had something to say about Ringles seem to think they’re a bad idea:
Each ringle is expected to contain three songs — one hit and maybe one remix and an older track — and one ringtone, on a CD with a slip-sleeve cover.

The Boy Genius Report
Universal Music NOT pulling out of iTunes. Their answer? A RINGLE!

The Megatron Don
Ringtone Rappers…that crap’ll (really) never survive.

MissInfo.tv
Ringles…not a nutritious snack

RADIOKILLS
Delicious Ringles for me

TechCrunch
Record Industry Proves Again How Much They’ve Lost The Plot

The ProHipHop Thinktank Sez:
Let’s see how it does in the marketplace.  I can think of too many reasons for and against to call this one though I think they’ll have to work pretty hard to make it work.