Am I right in my understanding that this is the last upgrade before all new upgrades are done in the cloud? And that if you do upgrade from 4 to 5 you will not be forced at a later stage to sign up to the cloud - you can therefore use LR5 for as long as you want?
Well, it's an excellent question, one which Adobe are playing a little footloose on answering.
Adobe are saying, currently, that LR5 will be a standalone product, available outside the Cloud and available to Creative Cloud subscription when you take the Entire Package.
But, Adobe are also saying that they are "Looking at" a "Photographic" package that would include Photoshop + Lightroom. If they do offer this in the CC subscription, how long before they take the current stance they have with Photoshop also with Lightroom. I seems to me that Adobe once they make Lightroom available as a subscription would (This is conjecture), at some point offer Lightroom only as a Subscription.
Using LR5 for for as long as you want only works until you reach a point where your current Operating System and Camera are no longer part of the ACR updates, i.e.. If LR6 goes to subscription & you buy a 1DXs, your sort of screwed using say LR5 that only covers say OSX 10.8.5 and 1Dx.
My own view on this is that I own CS6 Suite + this morning I downloaded LR5, I'm hopeful that someone like On One Software will in the next 12 months see an absolute Golden Opportunity to slip the slipper to Adobe and become a Giant Killer.
I just don't agree with Renting something as important to me as the Software that I use every day, I'm using my consumer power and simply deciding to utilise Adobe for as long as is absolutely necessary then jump ship to someone that hasn't tried to strong arm me.