It's exciting that we're getting a new Valkyria Chronicles, yes, but let's not forget, part of the first game's appeal was in its yummy, coloured pencil visuals. Visuals the PSP just isn't going to be able to match.
Sure, it'll do its darndest, and the game's cel-shaded nature means the downgrade won't be as noticeable as more "realistic" 3D games on the system, but it still won't look as good as the PS3 original.
Something these new screens (released overnight by Sega, they're not mag scans) do a good job of reminding us all of. Don't think of them as a grainy disappointment. Think of them — as you should any other "authentic" screenshot you see during a game's development cycle — as an exercise in avoiding launch day disappointment.