I'm not sure what the deal is with McKay. He may have been Omer'ed and lost a step. It seems like his production in '06 was on vertical routes, which we moved away from for whatever reason after Beck graduated. He probably also benefited from flying under the defense's radar. In 2006, he was a freshman, and not a primary concern like Harline, Reed, Brown, and Allen would have been. In 2009, the same probably applied - after all, we banked on that for game winning TD against Oklahoma. They triple teamed Pitta and left McKay all alone. Last year, our receivers collectively sucked - they couldn't catch the ball or get open, and the QBs had trouble getting it to them. Maybe defenses keyed on McKay, since he actually had some experience? I'd have to watch more games to know. As I recall, he had a few drops himself, so that contributes, too.
It seems like the training staff made some changes to de-Omer people and focus more on speed. Doman is going to stretch the field more vertically, which will provide more space for everyone, especially McKay. If teams focus on stopping the home run ball to Apo and Hoffman, then the McKay can go nuts along the seams against a zone defense, or by exploiting single coverage with a safety or linebacker. That's contingent on actually being able to hit the home run at least once a game or so, but once you establish that threat, you can get some serious YAC with those intermediate routes.
I'm confident he'll have a good year. He's got two games in Texas he'll want to show especially well for, so there's no shortage of motivation. :)