There's a big difference between a "gimme" and a big emotional nationally-televised game to start off the season against a team that hates the Spurs and has had it circled on the calendar since the schedule came out. Despite all that, and being seriously undermanned, the Spurs held their own. How that's cause for anything but optimism puzzles me.
If you don't think Hill is going to see minutes once he's healthy, then you haven't been listening to Pop since the draft.
Mahinmi is still raw and still young, and if healthy he would have seen big minutes against Shaq and Amare, particularly with Oberto's late scratch. He's been with the team long enough that Pop would have thrown him to the wolves to see how he handled it.