Originally posted by: AnnihilatorX
SATA transmit data serially;
Which, to the end-user, is irrelevant.
less noise; uses less voltage
This depends more on the drive than the interface. "Voltage" used is the same; perhaps you meant less "power" or "wattage"? Most newer drives (PATA or SATA) are more efficient than older ones.
At the same RPMs, performance difference is negligible. NCQ (with SATA2 drives/controllers that support it) can help somewhat, but mostly in multi-user situations with heavy disk access (ie, NOT most desktop systems).
With an appropriate controller and drive cage, yes. Not all motherboards support this, and I find it unlikely most users would bother trying to hotswap their drives unless they are building a server.
Slimer cable and interface
This is probably the most useful change from most people's perspective.
Basically, performance (unless you get a 10KRPM SATA "Raptor" drive from WD) will be the same. As noted, PATA may not be around on motherboards forever. But other than that, I wouldn't worry much about it.