There are different levels of QB "controversy". It seems pretty common for a team to wait until the fall to name the starting QB. As KingBling mentioned, many coaches already know, but just don't want to announce it.
What made ISU's QB controversy last year less common (and in a bad way) was that the QB competition continued throughout the season. The QB had to essentially re-win the starting spot after every game. Jeff Woody mentioned this as well in his interview, where he said that Barnett and Jantz were never comfortable because they were worrying about making mistakes. I rather doubt that all 7 or 8 of the Big 12 teams that haven't announced a starting QB are going to be anywhere close to that kind of situation.
I was rather surprised Woody spoke that candidly about the Jantz/Barnett situation. I'm glad he did, because IMO, the way ISU handled that situation was not good.