I was wondering what will happen to the member of the cast. I tried to investigate and here’s what I got:

• Susan Mayer (Teri Hatcher), Lynette Scavo (Felicity Huffman), Bree Van Hodge (Marcia Cross) and Gabrielle Solis (Eva Longoria Parker) – All of them will surely return to honor their entire-run-contract for the show
• Mary Alice Young (Brenda Strong) – She also has a contract similar to the four housewives above, hence she’s expected to return
• Tom Scavo (Doug Savant) – He is expected to be back as well
• Katherine Mayfair (Dana Delany)– She has a contract for at least three seasons, meaning season 6 will be her third. So she’s expected to return. (To clear who Mike really married)
• Karl Mayer (Richard Burgi)and Julie Mayer (Andrea Bowen) – For most of the past season, they have been on guest-starring role. This time, there’s a chance they might be part of the regular cast.
• Karen McCluskey (Kathryn Joosten)– Karen is believed to be back as part of principal cast.
• Mike Delfino (James Denton)– He’ll be back to clear things between Susan and Katherine
• Orson Hodge (Kyle MacLachlan)– He is rumoured to quit the show because he’s now a father and he’s having difficulty to commute from his home to the show’s set. Let’s see what happens to his marriage with Bree.
• Edie Britt (Nicollette Sheridan)– She is gone, and will still be missed.
• Ana Solis – The newcomer is expected to be part of the regular cast primarily to conflict with Gabrielle (at least in the beginning)

As for the others, I didn’t find any news. Note that these are just expectations and not a guarantee. Everything will depend on the show’s leads, writers and directors. For sure, things will be clearer once they start filming this July.