Also, we can't help but detect a tiny bit of bias when the person making this claim can be quoted in the very same article as saying, "Everyone would be flocking back to WoW and talking about how much fun the new expansion was and how great all the new PvP changes are while Mark Jacobs stands around, waving his hands in the air going, 'Guys! Guys? Hey! Our PvP is even better!'"
In all honesty, a lot of what we've been seeing from Warhammer Online doesn't point to any kind of spring release date. It wouldn't be surprised for WAR to launch in fall amidst a massive EA hype machine. So don't be too shocked if you do happen to see news of a delay sometime later this year. When WAR does finally go live, what it will need do to be considered successful is hit at least one million -- especially with how much money has been poured into the game. Hopefully it's good enough to make it there, but even if it manages to we don't think WoW would really suffer too much.
In the end, we really don't see any of these games worrying about each other as much as they could be worrying about Spore, anyhow. That game could possibly conquer the world, which we suppose would end up funding WAR indirectly anyway.