Logitech announced today that it is buying high end earbud vendor Ultimate Ears. UE is best known for $1000+ custom headphones for professional musicians, but it also has a line of consumer headphones in the $40 - $400 range. Its business model is incredibly similar to Shure - both come from professional audio (initially microphones in Shure's case) and branched out into the consumer space. In contrast, etymotic's background was in hearing aids, and V-MODA seems to have come from the fashion world.
Without the custom business, Ultimate Ears is just another headset vendor, and its brand differentiation will be difficult for Logitech to maintain. But if Logitech leaves the core custom business alone, it can definitely build up the consumer side - Ultimate Ears could definitely use better distribution and broader consumer awareness; Logitech excels in these areas - just look at what they did with Harmony (speaking of which, I just got in a Harmony One remote control; a review will follow shortly).
In terms of how Ultimate Ears actually sound, I have no idea. I have tested most of the competition - Shure, etymotic, Sennheiser, Sony, v-moda, and Bose, to name a few. I should be getting in some Ultimate Ears product soon for comparison.