Considering the furor that is now starting up on the official forums regarding this major change in dynamics, we can only wonder why after so many years Blizzard has reversed their decision. Previously, Blizz maintained that they wouldn't allow transfers from PvE to PvP because it would be unfair to players who leveled characters up in a PvP environment. They wanted to avoid PvPers having to deal with people who transferred into the harsher climates that PvP servers provide after having leveled up on PvE servers. With the largely guaranteed bank roll that is Wrath of the Lich King, one wonders just precisely Blizzard seeks to gain by changing a long-standing mechanic such as this. Do they really need more money? Or is this just, as one forum poster suggested, a way to allow players who started on PvE realms to finally 'rescue' their characters? Perhaps it has something to do with the smaller populations traditionally on PvP servers? Only Blizzard knows for sure as to the reasoning.
We recommend packing marshmellows if you go anywhere near the WoW forums for the next while; the flames are coming.