So what do we have so far outside of Wal-Mart for DVD bonuses? The only other thing I've seen mentioned is the Unleashed Vader at Best Buy.

I'm debating on whether or not I will buy it at Wal-Mart. The more I think about it, the more I think that the disc will be an edited-together version of the Threepio/Artoo shorts I mentioned earlier, with maybe some other film clips mixed in, interviews with the actors, and so forth. Since the movie is the most important thing to me, I'll buy it wherever I see it first, bonus item or not.
I think the bonus situation stands the risk of getting out of hand, not just with SW, but with other DVDs too. I'm dreading the day when studios start to intentionally hold material back from the DVD itself to include on a retailer exclusive bonus disc, and every retailer has their own individual disc as a bonus. I mean, what if when Episode I came out, it was only a single disc, and Target had a bonus disc with the trailers and TV spots; Wal-Mart had a bonus disc with the web docs; and Best Buy had a disc with the "Beginning" documentary?