[Update 10:00 a.m.] A Paradox spokesperson has confirmed that PvP is the next "big update" after Vietnam. We won't know more details until after Vietnam is released, but at least we know for certain that it's coming.
[Original Story] Paradox Interactive has dropped a none-too-subtle hint that it may be adding player-vs-player functionality to Magicka. In a series of tweets, the publisher solicited achievement ideas, then pitched one for defeating a Paradox team member. "Wait, we need PvP for that...we better build it right after #MagickaVietnam then," said a follow-up tweet.
While it's far from an official announcement, the series of tweets certainly seems to imply that Paradox has plans for PvP. We'll probably see more details of when to expect the feature as we get closer to the release of the Magicka Vietnam expansion later this spring. In the meantime, we've contacted Paradox for confirmation.