I'm a bit curious.. where is the actual evidence for this? I'm not saying you're wrong, but my impression is the opposite - if anything, SD (full size) seems to be the trend. In December, for example, I checked out a lot of digital cameras for a gift and it's full-size SD more than ever, SDHC in particular. Even Fujifilm, which used to be xD only, now supports SD too.

In fact I'm not even aware of any device using micro- or mini-SD, except for the N810. No doubt they exist, but I suspect that this would mainly be in some mobile phones. And a mobile phone has very different needs in my opinion, they tend to just have one single card stuck in there permanently, as an extension for the internal memory. It doesn't really matter at all what type of card that is.

What other, common devices are there out there with mini/micro-SD?