They caught him on the phone at the BC Launch at Universal CityWalk in LA (where, strangely enough, he's being asked to sign things as "Tigole"), and it seems as though the interviewer doesn't quite have a grasp on online gaming-- Kaplan is asked how Second Life compares to WoW, and as he says, while Second Life is great, it's not really a competitor to what Blizzard has built. There's a huge difference between Blizzard-created content, and the user-created stuff. He also namechecks the Starcraft and Diablo universes (not the first time we've heard those hinted at).
But the most interesting part of the article is what Kaplan says about player housing: "I think housing can take 'World of Warcraft' to the next level." That's definitely not a "no" to the idea, and frankly it's much more credit than I ever thought Blizzard would give to creating an in-game customizable area for players. While he does say it's an idea they had in the beginning (the huge inaccessible instance in Stormwind was rumored to be a player housing area at one time), Kaplan also confirms that if they're going ahead with it at all, they won't release anything until they have a "Blizzard-quality feature." So while there's no way we can expect it in the next patch (or even the next expansion), it's very interesting news that the gears appear to be turning over at Blue HQ about player housing.