It seems that LG may at least be
considering Mac compatibility now. I develop iSync Plugins for Sony Ericsson phones, and last week, out-of-the-blue, had an email from someone at LG Electronics enquiring about iSync Plugins and possible new software development for them.
Unfortunately, it's a bit of a non-starter until they implement SyncML in their phones, unless they wanted to go to the trouble of writing a whole proprietary syncing application for Mac.
I'll see what else I can find out and maybe get some contact details I can publish for people to show their support for Mac compatibility in LG phones.
In the meantime, if your new phone has Bluetooth, and accepts the industry standard vCard format, you may be able to transfer your Contacts from the Mac Address Book that way. Drag Contacts to the Desktop then send them to the phone with Bluetooth File Exchange.