To the best of my knowledge, the current HD landscape for soccer in the US looks like this:
-ESPN2 is planning to broadcast MLS matches in HD next season, when they begin their new contract to broadcast Thursday night matches.
-HDNet also airs MLS matches in HD, but not many cable companies have this channel on their lineups; for example, my provider (Cox) doesn't carry it.
-Currently, the only Champions League match that is broadcast in HD is the final, and it has been aired in this format for the last two years. All signs point towards a repeat in Athens next May.
-As for the Premiership, there are currently no plans for FSC or Setanta to broadcast in high-definition, so you are sh*t out of luck for that. As for other European leagues, a La Liga match is aired in HD on WorldSport HD each weekend; however, you have to be a subscriber to Dish Network to see it.