The Firebird is an experimental airship, originally built by the Turamzzyrian Empire, that has been... ah, repurposed as a merchant craft by its wayward captain, Sir Brashton Rainsbourne. Now flying under agreement with the Empire as an envoy to encourage trade and friendlier relations with its neighbors, the ship will be making regular trips between Elanthian towns once it is finished refueling in Wehnimer's Landing.
What does that mean for you?
Merchants: The Firebird will occasionally play host to alterers and other merchant NPCs to help you change your schtuff.
Shops: The ship will have a shifting roster of shops with keen wares for you to find.
The Arena: Spirit beast aficionados are able to battle NPC trainers for rare and powerful prizes, plus a few other things discussed here: http://forums.play.net/forums/GemStone%20IV/Game%20Design%20Discussions/Spirit%20Beasts/view/56
Events: There'll routinely be merchant events on the Firebird as she comes into your town. Who knows what's next?
This is a pilot (hah) program for me, and just as experimental as the Firebird herself. If you want to see certain services (within reason) or wares (within even more reason) on the Firebird, let me know here!