Finally, Lightroom on-the-fly previews on iOS during shooting :)
Been longing for this for a while, but now I've got a working setup with a wifi grip on a Canon 5D km II, sending JPGs to a MacBook Air running Lightroom in the camera pack, lid closed (allowing air around the computer bottom/back plate). The iPhone is setup as a secondary screen to the computer remotely, using the Air Display app. Meaning, the iPhone shows a zoomable preview, while the computer does Lightroom server work in (or on) the bag. Raw files are kept on card for later. Clients can follow on the iPad during the shoot, or I can have in-pocket checks of lighting within seconds, with post-look applied.
Someone will build a simple version of this in the future, I'm sure.