The area is presumably named Plaguewood because of the drastic effect that Blight has had on the landscape. The soil itself resembles a sponge in appearance, and the ecology of the area has been dramatically altered since the days of the plague. Fungus grows to amazing proportions, predominantly in the form of large mushrooms or toadstools, dwarfing nearby trees. It often belches out dark brown gas, looking in appearance similar to the gas that spews from Plague Cauldrons; whether or not these fungi are a tool used by the Scourge to spread clouds of noxious plague gas is not clear.
Plaguewood was the home to an imposing structure that opens a portal to Naxxramas, the enormous necropolis of Kel'Thuzad that floats above the Plaguewood. Access to this portal is controlled by the Argent Dawn. Only those who are exalted with the Argent Dawn may enter free of cost, while others must pay a hefty fee. In recent times, Naxxramas left the plaguelands and has been called to Dragonblight after the release of patch 3.0.2.
Despite (or perhaps because of) the prevalence of the Scourge, representatives of the Scarlet Crusade routinely travel the road to and from Stratholme. Any undead that they approach, they attack — whether Scourge or Horde alike, so Forsaken travelers should keep careful watch at all times.