Okay, now I know some folks are already crying out that the magus should be able to do more in a given round, and that there aren't enough swift actions to go around, etc., but I'm more concerned with balance and sanity at the table than I am with how 'cool' the magus is to play, so I'm going to come right out and express my problem:
The spell combat ability, as written, gives the magus too much power.
A Quicken Spell, once per round, every round--so long as the magus takes the full attack action--is powerful enough (and yes, I know the character takes a penalty to attacks; that penalty becomes moot as the character advances in level, and is still not the equal of the Quicken Spell increase for spell slots). Its power is increased by an order of magnitude if it doesn't take a swift action to cast the spell.
On the whole, the magus is a pretty darned cool class, but I think the way it currently reads is as a class that's going to take a full attack action every round, even with the penalty. It's possible I'm wrong, and all but certain I'm in the minority, but this is playtest time, after all, and I've gotta speak my peace.