Qualifications
Because the job requires having so much expertise in multiple and diverse areas, this field attracts some awfully bright boys and girls. To get one of the primo positions, you'll want to shoot for a master's. Even that alone won't get you into most of the good companies—they will also want to see that you have plenty of experience, so you'll likely have to put in your time (think five to eight years) in a related field, or doing project management for lesser companies.
You need to be able to demonstrate extensive knowledge of HTML and CS5, in addition to other programming languages (source). A little French probably couldn't hurt either.
You'll need both sides of your brain firing on all cylinders, so if you're artistic but can't figure out how much everyone owes on a check, or can do advanced calc but can only draw stick figures…you may want to keep on lookin'.