I bought this last year, but it got lost in playtime since it had to compete with my new DS titles like Final Fantasy III, Yoshi's Island DS and Castlevania: Portrait of Ruin.
But I've been trying to break free of my newfound Hot Shots Golf and Puzzle Quest addiction, and I'd like to thank/hate Drinky and MAF for both of those crack-like games, so I popped in Yggdra Union tonight.
It's awesome.  It really is.  The gameplay mechanics are pretty cool.  The visuals are a bit too simplistic; even the original Fire Emblem is more artistic, but the game more than makes up for it with the card system.  It's pretty nerdy, but totally awesome.