According to MI6 and other 007 news sites Giancarlo Giannini has confirmed to Italy’s Il Giornale that he is signed to return as Rene Mathis in Bond 22. The news lends more weight to the strong indications circulating since the London premier of Casino Royale that the new film will continue Casino Royale‘s storyline directly.
At the of Casino Royale, Mathis is being interrogated by MI6 after falling under suspicion of being a double agent. Although it is not clear at what stage the script is at, Giannini indicated in the interview that he will turn out to be on Bond’s side after all.

A link to the article in Il Giornale is listed below:
http://www.ilgiornale.it/a.pic1?ID=150871&START=0
I will retire now