For my MythTV media computer I use a network based HD-TV tuner from SiliconDust . I've been very pleased with how it works, the form factor and feature set. However, over christmas it suddenly went dead due to no fault of it's own. The 5V 2A power supply had failed. (It is plugged into a UPS with surge suppressor, so I'm relatively sure it was caused by a component failure and not bad input power.) If you look at the photo of the failed power supply (left) next to the replacement component that SiliconDust sent me (right), you can clearly see where something inside melted (and/or forced) the plastic case to bubble out, leading me to believe it was a relatively catastrophic failure.
This reminds me of the trouble I had with the original iRobot Roomba. I had my initial robot replaced under warranty two times (3 total robots) due to power supply and battery charging issues. Each replacement had a completely new (and different) power supply system, and it was clear that iRobot was iterating through designs until they found one that was robust. I only hope that this power supply failure was due to one bad unit, and isn't indicative of the average lifespan of the power supplies supplied with the HDHomerun.