I don't think you can ever have too much screen space. Your workflow adjusts to make use of it.
I've currently got a 27" iMac with two 20" Dell monitors turned portrait either side. I keep things like IM, Twitter, Email etc in the two portrait screens and keep what I'm working on in the middle.
I've currently got a 27" iMac with two 20" Dell monitors turned portrait either side. I keep things like IM, Twitter, Email etc in the two portrait screens and keep what I'm working on in the middle.