Wind of Nostalgeo is indeed a joint venture of RED and Tecmo, with Tecmo handling the publishing - but it turns out RED is simply planning the scenario and characters, which they often do. The development is being handled by Matrix, the guys behind the Final Fantasy III and IV DS ports, which explains why the 3D is so competent. The character design is done by Torajiro Tsujino, the original character designer for the Tengai Makyô series. He hasn't been doing much for the last several years, so it's pretty neat to see his hand in this...
Update: A correction for idiocy - this is their first original DS project, but not their first original game by a long shot. Somehow I missed that Matrix is the team behind the Alundra series and Dual Hearts. Sorry Matrix! Thanks to Christian for pointing it out.