Does the thunderbolt display have a cooling fan

Thunderbolt is different than other connectors in that there are two 10 Gbps signals multiplexed on one physical connector/cable assembly. The DisplayPort signal will go down the chain of devices uninterrupted so the full DP bandwidth will get to the monitor that will ultimately end up at the end of the device chain. Of course new display hardware could be released to add a hub / further Thunderbolt connections - but existing DP monitors should work as described.

All the rest of the devices will share in the PCIe bandwidth - sort of like how existing system boards have multiple PCI slots operating at full speed. Until vendors start shipping real devices with hubs and connectors - we are limited to speculation and browsing the engineering/marketing materials released by Intel and Apple.

From what I've read, the initial devices will be like FireWire devices - two Thunderbolt ports per device - one to the computer and one for the next device to connect down the chain. The bi-directional, hot-pluggable, dual-channel cables with substantial bus power means the best aspects of FireWire could be commonplace as a much more powerful standard for years to come.

Just got off the phone with Lenovo tech support after unboxing my T430s/i7 because it didn't have a Thunderbolt symbol on the back... just a DVI symbol. Confirmed: NONE of the 430's they're shipping even HAVE it yet. I'm sending mine back, suggest you do the same. The internet is saturated with references that they have it that all sound as though they are informed by press releases... and Lenovo chat even tells you they have it... but no joy. Technology never fails to disappoint.