That was my first thought, too.
But I think the OP makes an interesting point about those sorts of "trade-offs" turning into traps to ensnare the unwary. A high level of system mastery (relatively speaking) would be needed to avoid them, and lots of players don't yet or never will have that.
If a player looks at a wizard and sees fireballs and gouts of flame, he is going to be tempted. "Sweet," he thinks, "I'll be a total spell-flinging bad@$$ just like all those mages I know from fiction!" Then, come gameday, he sits there with a sad face because his fighter friend with a bow is doing essentially the same thing he is (damage at a distance), but much better.
If you are going to give the wizard the option to be a blaster, you need to balance it so that blasting is fun to do. Otherwise you might as well omit the option and save people the frustration of being naive enough to take it.
The problem I see with this is, it will probably lead to trying to balance wizard blasting with fighter smashing by limiting the number of times per day a wizard can blast--IE, the wizard's daily output is stronger per spell than the fighter's output per swing. Which is currently what we have in Next, and has its own set of problems (making an assumption about the typical adventuring day).
I agree that "trap" options are a bad thing for the system to have. But if they're going to balance two classes doing similar things, they need to be very careful about it, especially if one of those classes can do a whole bunch of other things.