TVLine Items: Housewives Eyes Final Season, True Bloody Dexter Casting News, and More

ABC may soon decide that the upcoming season of Desperate Housewives is its last — or possibly wait to see how the eight-year-old sudser and the network’s new dramas (Pan Am, Charlie’s Angels and Once Upon a Time included) perform when the fall season starts.

“It’s all dependent on the ratings,” a source tells TV Guide Magazine. “[Housewives] will be up against some stiff competition” — CBS’ transplanted and extremely buzzy The Good Wife included.

Are you ready to say goodbye to the Housewives? Vote in our poll below!

Desperate Housewives Exclusive: V Hunk Is Vanessa Williams’ New Beau

Ready for more of today’s TV dish? Well….

Callum Keith Rennie, who is currently snarking at David Strathairn on Syfy’s Alphas, has joined the cast of the NBC midseason drama The Firm, our sister site Deadline reports. In the follow-up to the big-screen adaptation of the John Grisham novel, Rennie will play the older brother of Josh Lucas’ Ray McDeere.

Fall TV Preview: TVLine’s Guide to What’s New

• Also per Deadline: Showtime’s Dexter has tapped True Blood‘s head-turning vamp, Mariana Klaveno, for the recurring role of a university professor…. Recurring Necessary Roughness player/Raising the Bar alum Teddy Sears is the latest to join Lifetime’s new Drew Peterson pic, playing the title character’s best buddy.

Harry’s Law has promoted Christopher McDonald aka charismatic attorney Tommy Jefferson to a series regular for the NBC dramedy’s second season, Variety reports.

Fall 2011 TV Grid: Where Did Your Favorite Shows Land?

• That li’l whippersnapper Avril Lavigne will kick of America’s Got Talent‘s string of live shows this Wednesday night by dropping in to perform the singles “What the Hell” and “Smile,” EW.com reports. The same results show will also feature a performance from the Broadway musical Priscilla Queen of the Desert.