First we have Timothy Dalton as an associate of Chuck's mother with whom he shares a mysterious past. For those with poor short-term memory, Dalton surprised us all as Rasillon (a.k.a. "The Narrator") in David Tennant's final run as the character.
Second, Eric Roberts will be among a group of "soldiers of fortune" in Chuck's life (other soldier's will include the WWE's Bastista. I'm reminded of Robert's role in the recently released The Expendables). For those with poor long-term memory, Roberts is the only American to play the role of the Doctor's nemesis, The Master, in the 1996 television movie starring Paul McGann (which will likely be released in Region 1 in the next twelve months, by the way).
I never needed a reason to watch Chuck before, and I need less of one today.