IGN has posted some new information garnered from the latest issue of Famitsu. A scan of the latest issue's page featuring Revenant Wings can be seen below, and apparently the magazine had more details on Revenant Wings than we'd first believed.
Vaan is confirmed to be 18 years old in Revenant Wings--a year older than he is in Final Fantasy XII. Penelo (now 17) acts as his navigator. Revenant Wings is being helmed by Motome Torishima, who previously worked as an event planner on Final Fantasy VII and an event director on Final Fantasy X. This is the third full directoral position for Torishima; he previously directed Final Fantasy X-2, and is in charge of the upcoming FFXIII.
Torishima explained that the reason Revenant Wings is being developed for the DS is the widespread popularity of the system in Japan. The idea is for the title to be approaced as "My First Final Fantasy," aimed to draw in people who don't normally play games. Torishima stated that the battle system has been simplified, and, with the use of the touch screen and stylus, battles can be won without using the typical variety of controls.
While Revenant Wings apparently takes place after Final Fantasy XII, Torishima was clear that it wasn't really a sequel like X-2. The game simply takes place at a time when Vaan and Penelo are air pirates, and they have the adventure all to themselves; in XII, they're drawn into a much broader conflict featuring a wide range of characters.
[Source: IGN]