This delay can only mean one thing. Or four things, depending on how you count subpoints.
-- B&N is going out of business.
-- It's going to be bought by the Trilateral Commission.
-- Our Nooks will be secretly re-engineered to transmit our most embarrassing personal data (if not our precious bodily fluids) to the new owners, and
-- WE'RE ALL GONNA DIE!!!!!!!!
Note: None of the above is true, except the last. But you knew that already, and I hope it won't be so for most of you for a long, long time. 
Conspiracy theories aside, I think that the upgrade schedule up to 1.4 was driven by the huge, glaring defects in each previous version. Instability in 1.0 and 1.1, screwed up titles and slow page turns in 1.2, page turns that needed to be slowed down a little (so they said) in 1.3. And then, of course, the notorious games.
There are no longer any huge, glaring defects (except, of course, the notorious games, for some of us). I take respectful issue with orb9220 on one point: no one had demonstrated a need for organization. Lots of people have expressed a desire for it. I have a lot of desires, too. "If 'ifs' and 'buts' were candy and nuts, we'd all have a Happy Christmas!" By that measure, there's still a little over three months to go to make us all happy.
So, with JohnP51 I'm content to wait and keep reading.
"And God bless us, every one!" 
I'm resigned it my fate at this point 
, much like the fox and his sour grapes (read your Aesop!). I guess v1.4 is not a bad point to stop at though it's far from perfect.I can read a book quite well on it. Annotations and highlights are out (I have no access to them so what's the point?) and organization is a wistful dream that feels otherworldly at this point. *Sigh* c'est la vie ...
So, to speak vernacularly for a second, I'm like ... whatever . We move on, lest we go bananas .
I'm sure that B&N simply told its software developers not to release anything.
There are any number of possibilities as to what's "holding up" the next release. The most obvious would be if they're spending more time testing it. Most places I've worked (I've been in software development for almost 40 years) will spend about 3 months just in the testing phase. That's after the development is completed. There has been a lot of grousing about bugs over the life of the NOOK design, and maybe this time they want to put out a release with as few bugs as possible.
Another possible consideration is that Wi-Fi is critical, now that there's a NOOK model that only does Wi-Fi, now that there's a web browser that only uses Wi-Fi, and now that there are e-books that can only be downloaded over Wi-Fi. A look around these forums will tell you that there are a lot of non-technical people who are totally befuddled when they try to get NOOK talking on Wi-Fi. Now, I personally don't know what the software could do differently (aside from handling shared-key WEP), but maybe someone had some bright ideas to make Wi-Fi simpler to use.
Another possible consideration (one can only hope, but I doubt it) is maybe they're upgrading from the ancient and power-hungry Android 1.5 to a later version. There have been many releases of Android since 1.5, and battery savings has been a feature of most releases.
Another possible consideration is that they're trying to make a good filing system, not just a filing system. There are a lot of different ways that one could file e-books, and different ways offer different advantages.
But my personal guess is that B&N has dug themselves into a bit of a hole. There are now three different NOOK hardware platforms out "in the wild": the original NOOK 3G, the NOOK 3G CR, and the NOOK Wi-Fi. The CR and the Wi-Fi models have never had a software update—they shipped with 1.4, 1.4.1, or 1.4.2 as appropriate. All software updates thus far have been to the original NOOK 3G. Any software update release now will either have to be compatible across all three platforms, or there will have to be separate editions that absolutely must not cause trouble if someone attempts to use the wrong edition for their device.
Personally, I'm fine with waiting until they've got something that's rock-solid.
(Note: I don't know if there are really NOOK 3G CRs that are shipping with 1.4.2 software or not. I've seen it mentioned once, and it could well have been a typo.)
