Ask HN: when to buy new hardware?

I'm starting a new project in a couple weeks, and my macbook pro is almost 4 years old. I'd really like to buy a new one and get it set up before I bury myself in coding.

The problem is that I don't want to buy a computer and then Apple releases new stuff a few weeks later. All of the buyers guides say to wait: http://buyersguide.macrumors.com/#MacBook_Pro

Should I get a new computer now and risk missing a major update to the macbook pros, or suffer through a few more months on my old one?