A report came through yesterday which has some serious repercussions on how you purchase certain Google hardware. If you missed the report, then it looks like Amazon has decided to not stock or sell items like the Chromecast or the Nexus Player on Amazon after October 29th. Part of the reason is that Amazon would like to avoid "confusion" by not stocking items which do not work with services like Amazon's Instant Video service. This is actually in spite of Amazon seeming to continue to refuse to make an Instant Video Android app widely available.
Of course, with items like the Chromecast or the Nexus Player, you can always just purchase them through the Google Store. Them along with pretty much any Google affiliated hardware. But what do you do if they are out of stock? Well, it seems that in the future you will simply register your interest via a waiting list on the Google Store.