The answer was that no one, except for Walter Ray fiddling with it from time to time, does, probably because the two-handed delivery places too much strain on the lower back to lend itself to use by older bowlers. But, both Mark and Thomas opined that we might start seeing more elite female players using this style.
For, whereas a man using this style gets only a relatively small rev and speed advantage over the more powerful one-handed stylists on tour, an effective two-handed female bowler would have a tremendous power advantage over all but, perhaps, Michelle Feldman. So, if a woman were to start throwing the ball well two-handed, it could entice many other women to adopt the style, and this could have a huge impact on elite women's bowling.
I followed up this question by asking if any seniors on tour bowled with no thumb one-handed. Thomas answered that no one on the senior tour does now but that there's a guy in Southern California approaching seniorhood who might soon make a dent on the tour with his one-handed thumbless style and that Mike Miller, who cashed in the Tournament of Champions this year, would also be a senior soon and could be a thumbless force to be reckoned with.
If I don't beat him to it with my own thumbless style, that is. :-) Or maybe I should further develop my two-handed game.
