According to DigiTimes' sources in the supply channel, Thunderbolt has infiltrated about 10% of new PC motherboards and notebooks. There's no indication of whether it's 10% for each category or if that's just the overall average, but either way, the percentage is quite low. Not that we're surprised. Thunderbolt devices remain relatively rare in the wild, and compatible cables still cost around $50.
Equipping a notebook or motherboard with Thunderbolt is also expensive. The controller chip rings in at around $20, DigiTimes says—quite a bit more than USB 3.0 controllers, which cost less than a dollar each. With USB 3.0 proving fast enough for most folks' external storage needs, it's hard to see a place for Thunderbolt outside of niche markets.
Right now, the interconnect's most promising consumer application is as a conduit for peripheral expansion in ultra-slim mobile systems that have little room for extra ports and peripheral chips. Thing is, you can't actually buy any Thunderbolt docking stations yet. Matrox's DS1 isn't shipping until next month, and Belkin's offering has been delayed until 2013.
For enthusiasts, Thunderbolt's biggest appeal may be its ability to connect a powerful external graphics adapter to a thin-and-light notebook. Unfortunately, none of the external graphics prototypes we've seen appear destined for production. That's really a shame, because I'd be inclined to pay a premium to get Thunderbolt in a notebook if it meant I could plug in a proper graphics card.