No offense, but switching webhosts takes a lot of planning (check out my thread and how many questions I asked here before I even considered switching). Switching anything related to DNS is even messier, because of the delay in DNS information propagation, so any mistake you make becomes very, very expensive. It's unfortunate that you had to learn this the hard way, but by all means, please don't blame it on DreamHost, because I don't think they're to blame (well, maybe their marketing people are after all).
I'm not being rude, just brutally honest... and I'm not saying that you're incompetent or anything, but if you have a popular blog, or any other mission critical web-based component of your business/daily life/whatever, please either take the time to research the process in detail yourself before you start or hire/ask a consultant to do the legwork for you. The worst you can do is assume; that's guaranteed to land you in hot water whether you're switching webhosts or painting a fence.
I will agree with you that marketing people (not DreamHost specifically; in general) make it sound too easy and can be misleading, but then again, do you take all marketing materials 100% seriously? In this age of instant gratification it's easy to lose track of the fact that IT can be complex, because it is complex, no matter what anyone (marketing or otherwise) says. That's especially true nowadays, because everywhere you look IT is marketed as "just works" (e.g. Apple and Microsoft); aside from undermining the true value of experienced and educated IT consultants, it lessens the value of IT as an industry in general by commoditizing it. While commoditization of certain things can't be helped, some things just can't be (or rather shouldn't be) commoditized if you care about the outcome and the bottom line.