This way maybe Canon and Nikon etc could add tethered support to Lightroom, or possible some 3rd party could make a business of this.
You're kidding, right? Nikon or Canon make a plug-in or module to work with Lightroom? The phrase "cold day in hell" comes to mind.
Look, camera communications is a VERY DIFFICULT thing to engineer. Phase One has a long history of camera com because, well, all their cameras used to be tethered and HAVE to be controlled by the software and even Phase only added tethered support for a small subset of pro DSLRs...
Setting up a Watched Folder and the sort order to be most recent at the top and control the camera with the camera software to set F stop and shutter speed and ISO works perfectly well. As soon as the image is saved to disk it's auto-imported into Lightroom. Click on the image and hit the D key and you're in Develop.
The one thing I'll note however, the whole tethered approach works a lot better/faster under Windows than Mac. Some of this may be because of Apple's USB 2.0 pipeline but it's also the fault of the camera makers.
On a recent Lightroom shoot with Martin Evening, he had to boot via Bootcamp into Windows and use Remote Capture from Canon under Windows because the Mac version sucks, is real slow and prone to losing connections...and that's Canon's own software on the Mac sucking. Imagine the problems Lightroom would have asking Canon for help tethering to their cameras when Canon can't get their own stuff to work well on Mac.
I also wouldn't hold your breath for Phase One to pony up and make a tethered plug-in for Lightroom...
Asking for tethered support is fine...but you really must understand what you are asking for. It ain't easy and would certainly take away from other LR features for what is arguably a small subset of users.
Tethered works now, about as well as one can expect using the camera makers' software.