From the print version of SFX 08/01/14 ( sorry no link). I've summarised the relevant bits.
The SFX article comes from the set on episode 12. Location Senoia, scene is Michonne and Carl foraging for food. They appear relaxed and the crew say it is a big bonding between the two. Something huge happens in the episode but SFX are not told what this is- no surprise there!
Later that day (the 5th in the episode's eight day schedule) they watch Lincoln perform a scene in which Rick has made himself at home in an abandoned house. Asleep in a bedroom. Sleep is interrupted when strangers arrive. Lincoln hides beneath a bed as an unknown man falls asleep in it. Rick hears several voices and a conversation that convinces him that these strangers aren't to be trusted. He crawls out from under the bed(sweaty, bearded, hair a matted mess) grabs a trophy ready to club someone with it. He makes his way through the other rooms in the house, pausing to hide, peering in doorways. It is a tense variation of cat and mouse. Are these men intruders or is Rick?
There is also a little Q and A with Andrew Lincoln and they say 'we find a Rick a widower who is ONCE MORE RIDING A HORSE' what could they mean?!!!
I know it is not much but I thought people might be interested in a little bit of news!