Hulu is reportedly on the verge of announcing a subscription plan for its streaming video service that would give users access to a greater range of content. Under the plan, the five most recent episodes of newer shows will remain free (ad-supported), but anyone who wants to access older episodes would have to pony up $10 per month for "Hulu Plus".
It's unclear whether the $10 subscription will let you watch an unlimited number of episodes from the site, and if advertising would still be displayed on the back catalogue episodes. The move to a subscription model isn't at all unexpected, but they'll probably have to offer something more than five-week old episodes for this to catch on. If you're able to stay on top of your favorite shows in a timely manner then you don't really need to sign up.
There are also rumors that Hulu might tie its subscription service with a new iPad application, but as Peter Kafka at MediaMemo notes
their subscription aspirations could be significantly devalued by a free streaming video application from ABC already available on the App Store.