I was watching motor week's pat goss, and he said that fanbelts, and heater hoses, and radiator hoses should be replaced at 4 years of age. has anyone replaced theres yet? I have a '00 and they look good to me.

 

I have an '00 also and it still looks good, too. I inspect the serpentine belt a few times a year and look for the telltale signs of impending doom - fraying edges, cracks appearing on the outer surface, broken or missing sections of ribs. So far, so good. Same goes for the coolant hoses - abnormal cracking or stretching or bulges, small fluid residue around the clamps.
I think car shows like with Pat Goss caters to the "average" car owner and sometimes even the "worst case scenario". Smart car owners will do their own evaluation and inspection. Pat Goss's hints are good for everyone else who can't tell a bad belt or hose from a good one.
Having said that, I have a new belt on hand as standby. I'll probably change my S/C belt first and at that time, I'll just throw on the serp belt. Also, on our cars, there are "guide marks" on the belt tensioner to tell us when the belt has stretched too far beyond its service limit - time to change. This guide is just that - a "guide". One has to determine if the remaining play in the tensioner is still enough for a belt that still "looks" good to do its job adequately.