Here's a new card from them:
http://www.principal.com/bank/ccards.htm

No annual fee.

Rebate Spending levels
2.0%=$25,000-$40,000
1.5%=$15,000-$25,000
1.0%= $5,000-$15,000
0.5%=Less than $5,000
This one is not issued by Principal (theirs was 1.25% flat rebate) but by some third party. If you spend 40K, rebate comes out just above 1.4%

But wait, they offer rebates on no-fee balance transfer. I can't believe my eyes, good old days are back.

And for diehard mileage addicts, they have another card with a travel program.