Well John, snotty reply aside, I did read Mr. Hogarty's blog post. It was one of the first sources I checked after reading announcements in the blogosphere. Per the official, Adobe sanctioned blog Lightroom CC is "Cloud Based—Everything you do in Lightroom CC is synced to the cloud. This means that you can access and work with your photos from any device (including multiple computers), and can easily share photos with others. All of your photos and all of the work that you do with them will be automatically backed up all the time."
Unless you have an insight to Adobe's definition of the words Everything, any, and "all the time" that differ from standard dictionary usage, my read is that Lightroom CC backs up everything to the cloud. All the time.
What little documentation is included in Lightroom CC makes the explicit point that LR is now a cloud-native application. The source image now lives on an Adobe server, with copies distributed to connected devices. File sizes are altered depending on available local storage. If you choose, you can keep full sized versions on a local computer. Cloud uploads ... those ain't optional. I also attempted further due diligence by reading Adobe's site, but as I mentioned above, most of the LR FAQs point to nonexistent pages.
Adobe has accomplished quite a feat. They made LR CC unusable for many people who pay the bills through their images. A combination of unknown security risks, the impossibility of uploading a full shoot of images through an internet connection before the next shoot begins (again, I'm assuming photography is your business rather than just a weekend hobby), and the sheer inefficiency of placing all those images in the cloud is baffling.
We actually do store huge amounts of images in the cloud as it provides redundant backups in case of disaster. If working remotely, pulling files from AWS can also be faster than copying them from our in-house storage. Storage costs are in line with what Adobe charges for LR cloud with the important differences that (1) we only store images that are useful - the vast majority are culled first, and (2) all images are encrypted on before they leave our computers so even if Amazon gets hacked all the bad guy will have are files with 256 random character names that are unreadable.
If your interest in photography is editing your happy snaps then Lightroom CC is a reasonable idea. Good for you. That appears to be where Adobe gauges the market to be and I assume they are correct. That does not mean that a working photographer will feel the same excitement about the direction LR has gone in his or her fizzy bits.