Jesus, the people on these threads. Such miserable wretches... It amazes me that some people still don't understand that plenty of players enjoy the Vanilla game play far more than the current version (and previous expansions) of the game. Sure, plenty of people only familiar with retail will try it, and plenty will hate it; that's ok. But there are thousands of people coming back to the game who haven't played in years due to one reason or another. People like me that hate how the game changed after BC/Wrath and is basically unrecognizable today.
Stop crying if you only want to play retail. You can play it, others can play Classic. The enjoyment of the people playing the other version should have zero to do with you enjoying the version you choose to play. Classic doesn't have to fail for people to still enjoy retail and retail doesn't have to tank to prove that Classic is awesome.