Something Else (Score 1)

As a lot of others have said, it really depends on your career goal. If you want to be a researcher, or teach the stuff, or maybe even write code, then maybe the Masters in CS is the best option for you.

If you want to do IT management, or general management, then maybe a IS, would help, but I'd just go for the MBA, at my job in college our IT director was a CS undergrad, and an MBA, he had enough technical skills to talk to everyone on the team and understand what was going on at a high level, and more importantly, knew the business side of things inside and out.

Then there is the track that I'm on, and maybe might want too. I graduated almost a year ago, and have found a small company to let me be the IT manager (I am the IT dept), and I have to say, my BS in CS didn't prepare me at all, and I see no reason to ever get a Masters in it. If you want to do the grunt work of IT, Infrastructure (Net/Sys admin type stuff) finish your CS degree, get a help desk job to get a little knowledge, then as soon as you can, move up, get a job in a small company that is either a 1 or 2 man IT dept where you can get your fingers on the servers/network. In the mean time get some certifications, CCNA, MCSE/A (Now the MCITP if you can get your hands on some server 08 stuff to learn), Exchange, etc. With 5 years of experience, and those certs under your belt you're going to be able to go wherever you want in the infrastructure world.