Hi a,
I've never had a Mac laptop die on me.
I still have my first Mac laptop from around 1991-2. Batt is long dead, but still boots up and runs fine. Once in awhile people still use it, and it works fine for basic word processing with the apps installed on it from that time period.
Jump to 2000 and my first
color laptop, a Pismo. The Pismo is still used semi-regularly at work, usually to open an older doc (everything else there is PC now). Its batt is also dead, but otherwise runs fine. It's even got a removable floppy drive that every so often I put in and use for one reason or another. I
could still use it as my main computer, but it's noticeably slower than everything else I use, and I won't bother upping it past its current OS, Tiger.
My TiBook from 2003 still gets daily use. Aside from the batt being down to about 75% capacity, and the trackpad being a bit more shiny that it was new, it still looks and functions like new. I bought it "only" four years after my Pismo because it was the last run of the TiBooks, which I think is/was one of the most distinguished computers ever made; I didn't want to miss out owning one and I sure don't regret it. Because I was a regular in the TiBook forums and read so many, many posts about various issues, I remember wondering and worrying whether the hinges would hold out, and the paint, and the logic board, and the optical drive, and the track pad cable. As I said, it all looks and works like new, so it has certainly stood the test of time for me. Thus I take, with a grain of salt, all the worry about the MBP being a lesser computer.
And finally, when Apple decided to go all shiny, reflective glass-screens, I decided the time was now for a MBP. At that point, no one knew if they'd ever produce another anti-glare display, and that's a big factor for me. So months after production was discontinued, I got a fantastic deal on a new 2.5GHz, with anti-glare display. As with the others, I've upped the RAM and the OS, and, based on all my other laptops, I'm sure I will someday up the HD, although 250GB is fine for now.
In any case, to directly answer your question, I've had this MBP for almost a year and a half, and I plan on keeping it an minimum of four to five years, until the next and the next and the next technologies entice me enough to spend the money on another machine, who knows if it'll even be a laptop by then? I will be very surprised if I have to buy a new laptop previous to my chosen time because of my MBP failing. Of course I understand it could happen, I'm just very doubtful it will. If you're rolling in money, hey, I'm sure someone would be happy to have your MBP and you'd be happy with a new unibody with that extra batt life. But if that money tree in the back yard isn't growing so well, I'm not sure why you'd buy a new MBP at this point in time.
Good luck with your decision. 😉