The Hulu subscription rumor is like a slightly less annoying version of the Verizon iPhone rumor: They'll probably both happen eventually, but pop up in news stories thanks to analysts and blind sources and possibly the shape of the steam rising from a voodoo stew-pot.
This month's rumors are amplified both in specifics and in quality of sources. Both Bloomberg and Peter Kafka over at MediaMemo posted on unnervingly similar Hulu subscription rumors today. I recommend you literally take a bath in a tub full of salt, because we've heard a lot of this before, but it's all plausible and I wouldn't discount it out of hand.
Both Bloomberg and MediaMemo report that sources "familiar with the company" say a $10-per-month Hulu subscription is coming very, very soon. Both publications mention next week as the possible announcement date, with MediaMemo noting that the service might even roll out, to a limited beta audience, upon announcement.
Bloomberg, interestingly, focuses on Sony's PlayStation Network as a possible home for subscription Hulu, mentioning offhand that Microsoft's Xbox 360 is also rumored to be involved. Bloomberg's sources must be someone at Sony, because there's no other reason PSN would get more emphasis than Xbox—it's a far smaller audience, and nowhere near as established in digital media as Microsoft's product.
According to both sources, the talks are in advanced stages, with Hulu and the content providers (NBC, ABC, and Fox) hammering out where that $10 per user per month should go. Stay tuned for a possible announcement next week—or not. Who knows, at this point.