I have to wonder if this is to an advantage or disadvantage in terms of reducing environmental impact. On one hand, the devices could last long, but people will still trade up, so the less material used, the better.
On the other hand, these things could die prematurely left and right (relative to traditional hard drives & more robust 2.5"/3.5" SSDs), so people will have to replace them more frequently.
We can't forget a point that everyone mentions: the potential for data loss if people don't back up (which, even in a world of cloud backup, 4 TB external hard drives, and 1-click automated backup, is still a problem). Enough exaggerated thermal cycles, and we have chips failing like they did when manufacturers had to switch solder types.
I doubt that even the use of metal in ultrabooks can stave off heating issues, unless ultrabook manufacturers do as ODD manufacturers do. If that happens, then we'll be seeing little divots and notches in the bottom of our laptops the size of the chips on the SSD.
I'd still feel a bit safer if they slapped a little heat exchanger on it and placed it close to the primary system fans.