Take a good look before you leap. Depending on the system you pick, the wiring could be radically different and in some cases, perhaps non-existent.
I've no personal experience on installing this stuff but it is something I'm interested in. Went to a NAPIT Trade Association meeting last week, we had a talk by Gira about their solutions. Much of their stuff is wireless, so no switch wiring.
They have retrofit style devices and DIN rail mounted gear that you could fit from day one, so concentrate your lighting control say in one location, this approach obviously has very different requirements on the wiring front.
But I would definitely investigate thoroughly the option before you rewire.