Well, I think it would be easier to just do a comparison on what we already know versus what may or may not happen to either device. I'll use the LTE version of the Galaxy Nexus and the US version (AT&T) of the Galaxy S2.
-LTE vs HSPA+ is a no-brainer. While the adverse effects on the battery life aren't inspiring, it is the faster of the two. In my opinion, the Galaxy Nexus is a 4G device while the Galaxy S2 is 3.5G.
-The display is going to be difficult to compare only because the word "pentile" is going to be thrown around. I'm a fan of the higher resolution/bigger screen, but I've used the S2 before and I had zero complaints about the display. I'll call this a draw only because it really does boil down to preference.
-Exynos vs TI OMAP 4460 (and their respective GPU's) would be a pretty easy choice, but as of right now, only the Galaxy Nexus has ICS which not only utilizes both cores, but is optimized for the hardware. So if you're a benchmark junky, the Galaxy Nexus is going to have the better scores. In a fair fight, the Exynos/Mali combination would be the faster of the two. Since we're doing it as-is, the Galaxy Nexus has ICS and the Exynos isn't compatible with LTE.
-Software is a beat-down. Again, as-is, the Galaxy Nexus has ICS and the Galaxy S2 does not.
-The camera is tough for me to comment on because I haven't used the camera on the Nexus. I could be entirely wrong on this, but I'd have to give this to the Galaxy S2 for now (and not because it has 3 more megapixels). I have faith the camera on the Nexus will be more than capable, and definitely has more features, but for now I'll say the Galaxy S2 wins this round.
-And lastly, the design. I'm going with the Nexus here. While I'm sure some people have issues with no capacitive buttons on the device, it's just more appealing. And it has a multicolor notification LED. If you include that, with me, you win more often than not.
Just so we're clear, I'm stating that above as my own opinion, not as fact. A lot of you will agree with me, some of you won't. So do I disagree with the articles you mentioned? Yes, and I've actually owned 2 out of the 3 Galaxy S2's in the US. Will the S2 get ICS someday? Definitely. I just have a feeling there will already be a Galaxy S3 and possibly another Nexus device around before that happens.