Would you use a "mini notebook" over a netbook or notebook?

First, perhaps we have to define the term "mini notebook." I am not referring to netbooks. I'm not referring to tablet-style ultra-mobile PCs (UMPC). In my book, the category "mini notebook" is a very unique category because we see a few devices out there that don't really fall into the UMPC or netbook categories. Some may say that they're a netbook or UMPC, but I'd probably disagree.

Let me pick on two examples:

1. Sony Vaio P. This is a very slim mini notebook. It lacks a touch screen. The screen is 8" and it weighs 1.4 pounds. Some may call it a netbook, but Sony prefers not to call it a netbook. I call this device a mini notebook. It's smaller than a netbook. It could be a UMPC (since it is ultra-mobile), but that could be debatable.
2. Fujitsu U820. Fujitsu calls this device a "mini-notebook." It has a passive touch screen that is 5.6" and the device weighs 1.32 pounds. This device can be converted from a notebook to a tablet. So, it's actually a mini convertible tablet PC. Fujitsu shouldn't call it a mini notebook.
   

Are these mini notebooks practical devices? Or are they glorified toys (very expensive toys) for gadget lovers like me? They're still far too expensive to compete against netbooks. Will they survive? At some point, devices can be too small to be very useful.

As smartphones become more powerful and as they blur the line between smartphone and MID (mobile internet device), we will certainly see an evolution of mobile computing practices. What if someday, your smartphone is your entire PC? You dock it at work, use a full-size keyboard with two monitors, and then you remove it from the dock to take it home with you. Can you imagine holding that much computing power in your pocket?