Yup, that's a problem with this stuff too. What the heck do you do when customer want's the location changed. You can't (or at least shouldn't) splice CAT5 unless it's being used strictly for voice. Coax is OK to splice but now do you extend the whole mess to the new location or just the cable what's being used?
In new construction it's cheap enough to put several jack locations in each room if you run individual cable. Nobody really knows how the furniture will be arranged and the easiest way to avoid costly work after the house is finished is to cover all the bases before the walls are closed.
-Hal
