If you have a USALS rotor, you just need to enter the SAME geographical informations into the new receiver.
If you are using DiSEqC-1.2, you should take note which satellites correspond to witch memory position of the rotor. This is important, otherwise you will have to reprogram the rotor again (you don't have to change anything physically on the dish or rotor): if you have Astra2 on memory 14, but don't know that - how will you setup the satellite list on the new receiver?
If you look at my website on "My System", you will see my list of memorised satellites. I uploaded that information, to make sure I never loose it.
It wouldn't be the end of the world, specially now that I have a spectrum analyzer, but still it is unnecessary hazzle.
Cheers,
vma