Production of "Phineas and Ferb" ends, future of the show undecided [Updated

The Animation Guild's TAG blog revealed that Disney will not be producing new episodes of Phineas and Ferb. They quoted an anonymous Disney staffer who worked on the series:

Most of the Phineas and Ferb board artists are gone. Phineas and Ferb was a great production that ran for five years, but now that both the series and the special are over, people are looking for other jobs. Jeff "Swampy" Marsh, co-creator of "Phineas and Ferb," took to Twitter to deny that the show is over in a series of offensive tweets directed at Steve Hewlett, the Animation Guild's business representative who broke the news. We have reached out to The Animation Guild for comment.

Contrary to Marsh's claims, I am unaware of any inaccuracies by the Guild regarding notification of the cancellation. They represent the artists working on the show, and if anyone knows whether the show has been cancelled, it is the Animation Guild. In fact, there may already be a new unaired episode/special of "Phineas and Ferb". However, what the Guild reports, and what Marsh does not deny, is that new content has already been produced, thus the reason the show's staff was fired.

UPDATE 2: The title of the article has been updated to more accurately reflect that new episodes are no longer being produced and the future of the show is unknown; P&F writer and storyboard artist Aliki Theofilopoulos wrote on Twitter that the show is "on indefinite hiatus." He wrote that it is.

Update 3 (February 21, 2014): Animation Guild business representative Steve Hewlett posted a follow-up to "Phineas and Ferb" co-creator Jeff "Swampy" Marsh's comments on Twitter. In it, Hewlett reiterated:

For the past few months, the staff of "Phineas and Ferb" has been telling me that the show has ended, that it has an end date, and that the series has neither picked up nor greenlit any further episodes. Every time I go to Disney Sonora, more and more P&F artists are disappearing from the space. And the few that are left tell me (again) that the show is ending.

As the artists in the show have said [see update 2 above], the series is currently "on indefinite hiatus" and that Disney has no new productions planned at this time. However, it is also clear that new content is already in the works that has not yet been premiered. In other words, even though Disney has ended production on the current series, fans of the show still have something to look forward to.