4.1.x is not really introducing any new features, it's just bug-fixes and performance improvements generally.
Google seem to want to emphasize that 4.2 is not only a bunch of bugfixes and performance improvements like 4.1.2 generally was. Calling it 4.1.3 would not give it a significant importance. It's still a stupid reason to call it 4.2, but whatever.
I don't own any Nexus devices myself, though I have tried the Nexus S, Galaxy Nexus, and Nexus 7. I could only tell you what I know.
From now on here, this is going to be a rahmu-type post with some yasamoka-style parenthesis:
Nexus devices:
1) No racism: Region-free. No waiting for updates for your phone's region. All Nexus phones are treated equally. No phone-racism.
2) Good hardware choice: I'd put some faith in Google for choosing hardware that is easy to develop for and deliver updates to without breaking compatibility. That would show with their use of Qualcomm and TI-OMAP chipsets in the Nexus line of devices. These chipsets are easier to develop for than Exynos (and maybe NovaThor, which was used in several midrange 2012 Xperia devices). The Nexus One had Qualcomm, the Nexus S had non-Exynos, the Galaxy Nexus had the TI-OMAP4460 chipset, and the new LG Nexus 4 has a Qualcomm S4 Pro chipset (most powerful thing out there, mostly). TI-OMAP chipsets are open-source (contrary to what was said that they have recently quit the chipset market,
TI is expanding)
Note: Galaxy S2 had two versions, i9100 and i9100G. The former has Exynos, the latter has TI-OMAP4430 (almost same a GNex chipset). The latter was released at the end of 2011 (beginning of 2012). It was the rarer phone at the time, and had a smaller development community and a smaller amount of custom ROMs compared to the i9100. However, it is claimed that the i9100G is the easier-to-develop for phone, and would eventually turn out to be better supported (on the long run). If it hasn't happened now, it's probably happening soon. The S2 is still quite a beefy phone.
3) Latest software: Nexus devices always get the latest updates. This is because the Android code itself is developed to support the Nexus phones first. First, factory images are released (and dumped and leaked). Second, the newest Android version's source code is published. Third, manufacturers get to work developing their own flavors of Android for their non-Nexus devices, and the developers community gets to work developing custom ROMs . It's obvious that Nexus devices would always get the latest software first.
Check out:
AOSP, the Android Open Source Project
4) What's great about the Nexus program itself is that it has been shown that non-Nexus devices can become "Nexus" devices by getting admitted into AOSP. The
Xperia S has the honor of being the first phone.
The binaries have already been released and now I'm guessing Google is at work. At almost the same price point as the Galaxy Nexus, having quite similar specs, having an LCD screen (advantages & disadvantages to AMOLED), 4.3" display (for those how like to get snug with their phones), good design, it's quite a good deal.
My 2 yen.