That's true, but that's what monitors are for. The times when you can't easily have a large external monitor are precisely the times when you don't want a big, unweildy laptop. I find the Macbook screen is a nice balance.
When I spend an extended amount of time hacking on my Macbook, I find myself missing the extra resolution. The width is fine, but the height is just lacking. Whether or not that's important is probably a personal preference, but I know I wish I had gone with the pro, just to get a handful of extra lines vertically.
What's the max display resolution a MacBook can handle when plugged into an external monitor?
It's 1920 x 1200, just enough for a 23" Cinema HD.