I love that mechanic. I think it's a lot more in the forefront with things like software that gets auto-updated, where the publisher pushes an unfortunate patch, or fails to follow through on a promise which was previously given the benefit of the doubt. I don't think physical products have yet caught up to the idea that this notion is relevant to them as well.

The especially difficult part when it comes to reviews for physical products in that it just isn't sexy to benchmark an old piece of hardware. What makes the situation even worse is that most reviews aren't centralized (that is, you google "productname reviews") and so to a large extent the visibility goes to whoever publishes first. Your brand new benchmark announcement gets clobbered by the pagerank of the reviews that happened right when everyone was interested in the product.

I had long assumed that Valve added the "past 30 days" aggregate to show when games had improved rather than gotten worse. (i.e. early access games) Kind of interesting that it helps clarify changes in both ways, and implies very different incentives for the game publishers/sellers.