It is not listed as HD and I don't think Fox is up to speed with HD yet, so I doubt it. It will probably be widescreen 480p like some other Fox games i've seen, which is better than nothing.
I'd say it was in HD too. I saw a few pans of other camera in the park and they were labeled "HD". I will say though, their HD sucks compared to ESPN's. The Home Run Derby looked much better than tonight's game.