Had an issue from a user asking how the client could be switched to use Testnet. Couldn't find any instructions.
There's currently no way to use testnet without changing a flag in the code and recompiling.
Since testnet is mostly intended for developers, we'll likely create a separate testnet release for the market instead of adding extra options to the main application.
Sounds like the right approach. Perhaps trial the latest features in Testnet under beta, and then push them out to release on prodnet once developers have kicked the tyres.