Bang On.

People buy iPods because they love them. If your music doesn’t play on iPods, it isn’t going to sell. And so if (a) you refuse to sell music downloads without DRM; and (b) no other DRM system other than Apple’s is compatible with iPods; then we’re left with a situation where the only successful store is going to be iTunes. What Universal and EMI now seem to have learned, at long last, is that (b) is completely under Apple’s control; only (a) — the labels’ own willingness to allow their music to be sold without DRM — is under their control.

-- Gruber (as always, getting it) on the Amazon Mp3 Store

Think I'm going to give it ago, just because Apple needs the competition.