the easiest thing to do would be to use time machine to move your files across to your new mac (which is possible on any new mac, as you said when you first turn it on…).
Get an external hard drive and back up your other mac computer, then select the time machine transfer (or something of the sort) when you turn on your new mac and all your files will be transfered across. The other option is to sync it with wi-fi (which im pretty sure you can do as well) from your old computer to your new one. However, that takes a lot longer time,
As for snow leopard, it has been deeply discussed at the WWDC (world wide developers conference) just recently and is due to be released some time in September this year. It is called Snow leopard because it is simply a better leopard.
The new (updated) macbooks, with faster processors, a better screen, Firewire and an SD card slot have been recently released. So with snow leopard, they should be great.
Hope that helps

Snow Leopard hasn’t come out yet, but when it does, I am sure that is done automatically.