Was thinking of avoiding all news sources today until I could watch a replay after work, but decided I couldn't resist. Stoked.
My reading of the table says that no matter what happens in the other game, we go through second. If Australia win they go through top; if Argentina win then they go through top; and if it's a draw Argentina are top due to best goal difference while we're second. Will most likely be playing the Netherlands, though GB are a decent chance to upset them in which case we'll be up against them.
Now, got to find me some semi-finals tickets.