I agree, but here's some anecdotal evidence that it may not work 100% of the time. I have a unibody 15" MBP that shipped with the old style magsafe connector, and my boyfriend has one of the later pre-unibody 15" MBPs that shipped with the same type of cable. He got a replacement power cord with the new style connector that didn't work on his machine, although it appeared to fit. The same cable worked fine on my machine. However, other new style adapters have worked even with his old machine. So even though the old and new style connectors seem to be largely interchangeable, there's some variation (we guessed it was the adapter length/depth of the magsafe connector slot on the laptop, we could be completely off since we didn't actually bother to measure) that you should be aware of.