I don't know what the upgrade path will be yet. Plexer v2 isn't coming out the door next week though. Regardless, you wouldn't have to pay full price for the upgrade if you have v1; if there is an upgrade cost, it'll be around $10~$15 max.

Plexer v2 is a complete rewrite that will support networking and will have a 3rd-party plug-in system, so it is a significant upgrade.