GM Vladimir Malaniuk seems to have played it quite a few times (including a loss to Anatoly Karpov).
Neil McDonald's _Starting Out: Dutch Defense_ has a section on the Leningrad. I have not studied it but the other parts of the book are good--he emphasizes ideas rather than variations. It's not a deep book but it's a good intro. (He also covers the bizarre early anti-Dutch gambits, which you need to know about if you play the Dutch....)
Does anyone know current and/or past GMs/IMs who play/ed the leningrad Dutch? Are there good books out there for this opening? Does anyone on this site wanna play some leningrad dutch games?