A few users are reporting that Comcast sent across an unannounced update to their digital set-top boxes. We can't confirm exactly where or what boxes are affect just yet but we can tell you for certain that the greater Detroit area boxes received the update. So far we have found that high-def programs are now labeled as such, the DVR menu has been updated to include searches and now the main menu has an HD option. There could be more updates buried but being as Comcast hasn't came out and told us what they are, these are the only things we could find. Screenshots after the jump.