I don't think so - I don't see it as standing out from Wlad's other wins over similarly solid, decent titleholders, i.e.: Byrd, Chagaev, Haye, etc. I think the only way Wlad could get a signature win at this point is if he beat his brother.
Not sure if its a "signature win" as Louis' win over Schmeling, Holmes' over Norton or Duran over Leonard, but it's will be another superb win for him, like the ones against Byrd, Chagaev and Haye. Another one for his best wins collection.
On par with the other titlist's he has beaten. Perhaps slightly better. Not as good as Byrd who is usually ranked around the #50 Hw of all time.
It is a guy with a '0' so it counts as something but Pov's career the last 3 years has not been that great so not sure as far as where it would fall. Top 5 I would guess? As far as an event it will pass the Haye fight they said they expect to sell 80k tickets......