I synced my main iTunes library to iTunes Match when the service was introduced. At that time, if I tried to sync a second Mac, it made it clear that the existing stuff in the cloud would be removed and replaced with the library from this second Mac. I read something recently suggesting that multiple Macs and their libraries can now be integrated into the existing sync to produce a sort of master library drawn from more than one Mac (each with different or somewhat different libraries). Is that right? My Mini media server at home is synced. If I now add iTunes Match to my MacBook Pro, will it just integrate the extra songs or replace my library in the cloud? I'd hate to go through re-uploading what is on the Mini.