I can't say that there are a lot of similarities holding this list together. Some are items that work well, but should be much better, lighter, cheaper, etc (such as the AppleTV, Segway, and Sony's $800 PDA). Some were great ideas, and even good technology that were spoiled by bad industry support or tepid consumer uptake, such as the CableCard format and Intel Viiv. Some were just flat out stupid ideas. Others were brilliant ideas only because they adequately estimated the astounding level of consumer stupidity that's out there (Anything from Monster Cable and the "Audio Grade" AC plug). One of my personal favorites is the two-in-one device where the two features are either comically unrelated or actively in conflict with one another (iPod dock/CD player, Tazer/mp3 player, mouse/phone).
Bringing this discussion back to computing, one common refrain is consumer devices that perform one task or a limited subset of tasks that can be better performed by a general-purpose, and usually less-expensive, computing device. Yes, a handheld device that only does Twitter sounds interesting, until you remember that it's stupid. Likewise, the Audrey and every other device that's like a real computer but more expensive and less functional.
The heartbreaking devices on this list are the pioneers. Devices that promised to do something useful, such as a WiFi or Bluetooth camera, but fail because they're too early and the technology hasn't caught up to the vision. I would personally like a network-enabled wristwatch, camera, car, and media player. But we'll all just wait for the tech to evolve a bit, won't we?
The most maddening items on the list are all technologies that have been thoroughly discredited in the marketplace because they deviated from well-accepted standards and consumer expectations, but the vendors soldier on, producing newer versions that nobody wants except the suckers who may have made a bet on a now-obsolete standard. Interestingly enough, almost all of the products in this category are made by Sony. MemoryStick, MiniDisk, Clie, UMD, ATRAC3 Walkman. Interesting, and tragic.
Some of the products on this list actually became big hits in the hacker community after they failed in the mainstream marketplace and became inexpensive bargain-bin items. Both the CueCat and the Audrey were huge hits among hackers after they failed. You used to get a CueCat for free, but now if you want one you have to pay $10 on eBay for it.
So Happy Holidays and let's all look forward to another decade of lame gadgets.