No PC produced now will be able to function competitively in 7 years time - let alone 10 years, be it a desktop or a laptop. Unless, of course, you are prepared to stick to the same OS and software that you originally load onto it. You also need to bear in mind the wear-n-tear factor, and because laptops are portable they suffer more from breakages than desktops do.
On the positive side: If the machine is new I can't fault it and it should give you at least 2 years good service (depending what your needs are, of course) after which you will probably be tempted to get a new machine. You will then be able to use the old laptop as a backup, media centre, server or whatever (providing you don't drop it or drive over it too often during it's first two years of life!)