From Kotaku: http://kotaku.com/5135126/lets-look-at-the-valkyria-chronicles-anime who's source is Dengki:
These are some pieces of character art for the show. The costumes check out, and look great, but the faces? Little sharper, little cleaner. Looks like a little something has been lost in the translation from glorious hand-drawn-looking game to cel-chaded anime. Ah well. Game adaptations have looked a lot worse than this.
Personally I think the art is pretty faithful, it has lost the rough 'water colour' edge that I love and has gain a generic 'anime' look but at least all the characters and details are very recognisable.
The big test is if the anime will be faithful to game canon or try to 'improve' on it. I hope for the former, mainly because most attempts to deviate from canon in situation similiar to this end up being crap.
Also: Keep the original Seiyuu!!!