Warhammer: Dude...Blizzard is risking pissing off their players by speed-tuning pvp stuff that breaks pve and offering arena tournaments just in anticipation of us and to tempt pvp players to stay...and we're not even out yet...just think of what they'll do if we did release D:
Warhammer Dev: I GOTS IT! WES GONNA RELEASE WHEN THEY DROP THEIR EXPANSION! SURE MAYBE IT BE COMPETITION BUT IT ALSO MEAN ANGRY BLUE TROLLS GON' BE DISTRACTED WITH BUGFIXING
And this is where those guys from the Guiness commercials pop up and simultaneously say "Brilliant!"

But yeah...if they don't turn into the next DNF they're still gonna have to put up a pretty big showing to compete with Wrath. Every MMO I've seen that gets delays tends to do badly because while it DOES allow more time to polish, it also AGES it. Ragnarok being the prime example; RO was one of the first MMOs after UO and EQ, probably one of the more widespread ones due to the length of it's beta(And Alpha, which I participated in, before skills/extra classes/arrows/potions even existed lol); it got fairly popular and thrived well enough once it went live, and RO2 was announced shortly thereafter.

RO2 beta was due like back in 2003, 2004 around Feb. Feb came and went with no news and the English site being taken down to boot. It kept being delayed according to the translated Korean notices, and while it did eventually start(korean beta only, though that didn't stop non-Korean players from joining), most people didn't give 2shits anymore or had moved on instead of waiting. Warhammer's had alot of press time, being a victim of their own hype they need to release while people are still hyped and willing, waiting too long people will lose interest, or other, better things will show up and distract them with their shininess.