Looks like Davydenko's renaissance was short-lived
Because he lost a close match to Tsonga?
If that's the case, then the whole ATP is in a dire state. JWT has beaten every current top player bar Tipsarevic (who he never faced) and the only top 10er he faced in Grand Slam level and never beat is Del Potro - beat Federer, Nadal, Djokovic, Murray and Ferrer, never faced Berdych, Tipsarevic and Isner.
If losing a close match to Tsonga is proof that a player's renaissance was short lived, then the ATP tour as a whole must be well and truly dead.