Actually, I think Hingis is back on the tour, playing doubles. They are none too happy about it, but she was suspended for two years for testing positive for coke. She's eligible to come back. I don't know if she's entered any singles draws yet, but she was a top-ranked doubles player for some time, as well as in singles. I think that's how she's easing back in. I always thought it was telling that she didn't challenge the coke result/suspension - she just took the suspension.
"The best kind of pride is that which compels a man to do his best when no one is watching."