I've had a very successful career in IT with only a BA in liberal arts. In IT, there really is no need for formal credentials, the entire industry essentially follows a sink-or-swim model. If you've got what it takes, you'll do well.
The interesting part, is the "got what it takes" bit. It's probably not what you think it is.
For example, my employer is arguably the single most successful IT consulting company. One of the "big 5". We do a lot of different work, in a lot of different industries, with a lot of different technologies. You might think that hiring for all these industries and technologies is difficult - but you'd be wrong. In fact, this Big Time Consulting firm typically searches out smart competitive people, often those with little no technology or specific industry knowledge. We take people who know how to work hard and learn, and then we put them in situations where they'll learn the technologies, and learn the industry, and (hopefully) prosper. The idea that the 4 years you spend in college defines your career is to us, categorically false.
I'm (right now), in the middle of teaching a class of our new recruits how to program in Java. %80 of my class has effectively no technological background. Some of them have engineering degrees, but some also have geography degrees. If my class is typical (and I hear that it is...) then less than %10 of them come from CS type backgrounds. And, we take these people, and eventually - they'll build the next stock exchange, or 911 system, or flight control system on a large passenger aircraft, because that's the work that we do.
Which is all interesting, but ultimately, just one example of how to get started in IT. Strangely, my career didn't follow this path at all. When I graduated with my BA, I went to work for Molson Breweries (dream job for a recent grad!) and focused on their growing Internet and Intranet projects. I was writing Microsoft .asp, but keep in mind this was 12 years ago, so most of the open stuff we love now didn't exist back then. But still, .asp was lame and I knew it, but I also knew that job was the only step I needed, and when I left Molson I had the credentials I needed to get hired elsewhere.
The truth is, that there are a lot of companies like consulting firms that won't care what kind of degree you've got as long as you like to run with the bulls, and there's companies like Molson that will hire you if you've got the skills they need. Ultimately, once you get just a touch of experience, nobody will ever care what your degree is, only what you can do for them.
None of the companies I've worked for, nor the clients I've consulted for, valued a graduate degree in CS any more than an undergrad one. Knowing how to design an OS will not help you one bit when you're asked to design a trading system, for example.