What a great thread! My apologies for being late to the game and perhaps missing its critical mass of interest.
The NEX-5n is a fantastic camera. It has the same quality as the much heavier Nikon D7000 (which I own), because it has the same sensor in it. Whaddya know.
Unfortunately, I think the system lenses that ship with the NEX are only "sufficient", with the exception of two: the 16/2.8 pancake and the Zeiss 24/1.8. The latter is too big. The former is a perfect backpacking/snapshot lens, but its strength is only its form factor (small and light), not its IQ (it lacks corner sharpness, but not outrageously so if you're presentation is limited to flickr et al.). I own the 16/2.8. I like it, but it's pretty much relegated to snapshooting, or when I need to hand the camera to somebody else to take a picture of me.
I own a NEX-7 but haven't taken it backpacking yet. I'm still trying to learn its nuances.
The real reason I own it is that I have a 20 year old investment (that I've flipped a few times) into Leica M glass (I still own and shoot my old M6), including the two best lenses that I've ever owned: the Leica Elmarit-M 28/2.8 and the Leica Tele Elmarit-M 90/2.8 (and these aren't even Leica's best lenses). I have a few other M lenses too, including (what I think is) the spectacular little CV 35/1.4 and the two Zeiss ZM "C" (compact = light = small) lenses, and the best bargain in M lenses today: the CV 15 Heliar, which has miraculous IQ.
I've shot these lenses mostly on my M6, which, if you get good scans and use slow film and a tripod, you get great images. I had a several-months long affair with an M9 two years ago (loaner) but the darn thing is a brick to wear around your neck, has a terrible screen, bad high-ISO performance, a bug in SD card writing that causes image corruption (I was one of the unfortunate few that experienced it and lost quite a lot of images from one of my treks), doesn't shoot video (yes - today - this is stupid), has this terribly narcissistic aura about it (is it the red dot?), and weird colors in environments with a lot of UV (high altitude).
But my Elmarits - these are really my personal dream lenses - they have charming character, are very small and light, impeccable sharpness, and beautiful smooth (not "swirling") bokeh. So I tried to pair them through the mFT revolution with a number of "sensors" to try to get those sensors to capture what these lenses were capable of. So, through a series of Oly and Panasonic bodies in mFT formats, I remained disappointed. The sensors were the limiting factor, and the images were ho-hum.
Then one day, I shot them on a NEX-5n, and voila! A sensor (other than an M8/M9) that could capture the beauty of microcontrast in the Elmarits. The shots were gorgeous - as gorgeous as anything I ever got out of the M9.
Now, for a number of reasons I didn't like the UI of the 5n, the lack of a built in viewfinder, and getting good audio with video was more than tricky, and video is important to me. However, when I started studying the UI of the NEX-7, as well as its video capabilities, I knew that this was the body that I was finally looking to pair with my Elmarits for digital use.
So, I'm now in that period where I'm studying the NEX-7, learning its UI, and the nuances with its sensor, which certainly behaves differently than the 5n (including slightly poorer high ISO performance - ah well), and I suppose in January sometime, I'll post some images from the NEX-7 with my M lenses.
In conclusion, for me, it's all about the glass, and the digital body is only a necessary (and depreciating) evil. And finally, with the NEX-5n and NEX-7, I think we have - for the first time ever - a body that can capture what some of the really fantastic lenses out there are capable of - which means that the body may now start to transition (a little) towards a piece of gear that lasts for a little bit longer period of time without fear of rapid (months-long) obsolescence...
FWIW I'm still nervous about taking a computer (NEX-7) rather than a camera (D7000) into hostile environments. I've taken the D7000 through rain, snow, dust, etc. I don't think the NEX-7 will fare as well. And, so far, the Leica M6 is still the only camera I've ever owned that I can keep around my neck at 20 below and it still keeps on clicking just fine (although I find my own abilities to still keep on clicking at 20 below are waning).
For Christmas, my wife gave me a Holga 120N. I just may reserve that for my next trek, as my middle finger to the establishment: this whole digital obsolescence thing is such a scam!