You all to remember that those setlists were used before the release of St Anger - which partly means they were used as propaganda and promotion.
Now that St Anger is out, there's little need to pretend the band has 'returned to thrash'.
I'd be betting that once they hit the road in support of the album, we'll see a lot more material from s/t - Reload. However, we are talking about Metallica here and not Maiden, so it's highly probable that the set will change considerably over the period of the tour, and you might get lucky and be there when they skip the recent material and only play the heavy shit.