Update: As ever, our intrepid SlashGear commentors come to the rescue. It looks like Amazon incorrectly tagged several iPod models, causing them to be left off the hard-drive based sales list. As of update, they've still not corrected the issue; however in the full portable audio chart the iPod Touch pre-order is sitting happily at the top (complete with prescient user reviews).
Cynical we techies may be about Microsoft's Zune and its appeal as a PMP, but the general public once again demonstrates that at the end of the day price plays one of the biggest factors. Since the cost of the white 1st-gen 30GB player dropped to a mere $169.99 on Amazon US - thirty bucks more than the $50 reduction Microsoft announced - it's hit the number one spot on the retailer's hard-drive based PMP sales list.
Still, Microsoft should probably hold off from getting too excited. Zune was never meant to be a pile 'em high, sell 'em cheap player - the no-brand Korean and Chinese PMPs do that far too well - it was meant to be a true rival to the iPod.
If you view this reduction as a stock clearing exercise before the 2nd-gen model launches (and wouldn't it be interesting to see exactly how much stock there is to clear?) then we can only hope that Microsoft had some premonition about the iPod Touch, since the next Zune will fail to compete even more unless they provide a strong alternative to the touchscreen Apple.