The last time Calvin Johnson played at Soldier Field, there was that whole "process" mess which robbed him of a game-winning touchdown and his third straight strong performance in Chicago. (In the 2008 and 2009 road performances vs. Chicago, Johnson caught 16 passes, one touchdown, and averaged 109 yards receiving.)
The projections for this year suggest that Johnson will have similar success. Per ESPN PPR leagues, Johnson has had just two games under 20 points and in those games, Johnson still caught two touchdowns and had over 100 yards receiving, respectively.
The Bears are in the middle of the NFL in points allowed to opposing wide receivers, but have done an above average job the past three weeks (all wins). Even if the Bears bring their A-plus game, though, Johnson is going to get open. Even if he isn't open, Stafford is likely to play 500 with him at least a couple of times -- and Megatron has shown time and time again that heavy coverage does not prevent him from making catches.