Update: How Nintendo still surprises
I think it might have been too soon to come out with this piece, actually. We got word this morning via CVG that DSi will have region-locking, which isn't as significant as the other news that came with it: there might be DSi-only game cards that would in turn have said region-locking—assuming the veracity of the unnamed Nintendo spokesperson, of course; hard information about the DSi has been hard to come by, to say the least—and that DSi would get parental control features.
This news prods me to suggest that perhaps DSi is taking a new variety of the old 'third pillar' strategy that we saw with the original DS—except instead of positioning it as a separate product line with hopes that it will succeed its predecessor, DSi is instead positioned as part of its predecessor's already well-known and highly successful product line. If DSi takes off, it branches off and succeeds DS fully. If it doesn't, no harm done; DS keeps on going, and we'll try something else in a couple years.
This tack may invalidate some of the above analysis I worked all weekend on, but I'm not too proud to leave it up anyway. It'll be interesting to see what comes of all this after DSi has been on the market awhile.
One thing's for sure, though: Satoru Iwata is a genius.