I'm assuming that everyone that cares has seen the season finale of Brothers & Sisters by now and thus knows that 1) Rebecca is not a Walker and 2) there is likely another bastard Walker, but of the male variety.
This story line concerns me just a little bit. Firstly, while all of the "incest" complaints don't bother me quite as much as others, it just saddens me that the show has undone a relationship that they have spent 2 seasons building. Secondly, I feel like revealing and meeting this new "Walker" will only end up feeling like a redo (and reusing) of the original "Meet the new Walker" plot.
That being said, it is still fun to hypothesize who will play this Ryan Walker character. While casting has not yet begun, one rumor is that a name being thrown around is none other than Gregory Smith (who starred in another Greg Berlanti show - Everwood - along with "Rebecca", Emily Vancamp). I would be in full support of this casting, as I always loved both Everwood and Smith's performance!
Any other ideas or suggestions for the part? Throw them out below!