I don't think I've ever heard of a fuel pump going out on an LS. If you're worried about it then just don't run the tank dry, fill up with a quarter tank remaining. I personally wouldn't change it unless it broke.
If you're interested Lextreme has a tutorial on changing the fuel pump, it's really an upgrade since he's running high performance stuff. The upgrade he did in the tutorial is not needed for people with a stock engine. However, it shows you exactly how to take out the stock fuel pump.
http://www.lextreme.com/fp.htm