Trine was pretty fantastic when it came out in 2009 but Trine 2 was a major overhaul in just about every way, offering dramatically improved visuals and cooperative multiplayer that allowed the game's three lead characters – the Wizard, the Thief and the Knight – to be controlled simultaneously. Frozenbyte described those features as "missing" from the original game, and that's where the newly-announced Enchanted Edition comes into play.
The Trine Enchanted Edition is a port of the original game to the Trine 2 engine, enabling all the extra goodness, including (and especially) multiplayer, that made it such an improvement. That's cool enough in itself, but even better, it's going to be released on Steam as a free update; and even better than that , it will accompany rather than replace Trine, so you'll be able to choose either the old-school version or the Enchanted Edition from the game launcher.
The Enchanted Edition beta is now available on Steam, and Mac and Linux versions are also in the pipe and will come out "shortly" after the full Windows release. A proper launch date hasn't been set, however, because most of the Frozenbyte staff will be taking off for holidays soon. I guess that's just how they roll in Finland.
Instructions for launching the Trine Enchanted Edition beta are up now at Frozenbyte.com .