Belts and hoses - scheduled replacement?

[edco]

Greetings and Happy New Year to all !

As my wife's car (04 325 ci) is just about to turn 5, I was wondering since it's the same 3.0 engine as in my X5, if there is an expected life span, or do folks replace them every x years as part of normal maintenance. The belts are tight with no cuts or other obvious damage, and the hoses feel the same as my X5 which is 3. Since she has the extended maintenance until the end of next year, I thought I would just toss this question out since it probably applies equally to X's and other BMW models. She only has about 40K miles on her car, fwiw.

Thank you and may 2010 be a prosperous and extra happy new year for you and yours !

Ed in Metuchen, NJ