I tried searching for this in the DL forum and couldn't find anything (I'd guess this has been posted on the AS board).

I just noticed on the AS website that they are offering 2,500 AS miles as a bonus for booking and flying an AS award trip on DL. Since I'm sure they only have low DL award flights, it's like they're telling their Mileage Plan members that it's so tough to get a low DL award, you'll get a bonus if you find one!

One thing I have found is that it's sometimes easier to find low DL awards using the AS award search than it is on delta.com. At least it sometimes comes up with different options. The difficulty is that you can't do a flexible date search for non-AS flights, you have to search by the exact dates.