i bought a MBP a year ago, so i can learn rails on it. I've been a PC guy for the longest time. But rails development on a mac is just so convenient. Unfortunately at work, we're a PC shop. So do our development on a debian VM using virtualbox. It works fine. So if you have the money, go for the MBP. Other than that, I highly advise not to do rails development on Windows....use a linux a distro in a VM