No PvP? Since when? What has happened?

I just logged on my usual character on Icecrown, from a couple of months break.

I saw some horde players in the world (I am alliance) and for some reason their name were just blue (which means I cannot attack them).
I continue playing and the same thing occurs to every horde player I see. That is when I understood something was wrong.

I checked the news but I cannot see anything regarding this?

When I log out it says the Icecrown realm is now an RP realm, which would explain why there is no world PvP on.

What has happened? Is the realm changed into a pure PvE realm now instead? How can I get world PvP back?

EDIT:
Someone told me in-game that this is an april fools joke... I didn't even realize it was april 1...
I'll be back playing another day then.

oy man, cheer up April fool.

Last night I saw a guy in STV who had pvp off and I grilled him really hard about how he did it and I thought he was pretending not to know what I was talking about. I must've looked like a loony