It seems as though every other map blogger has offered their opinion on Sean’s list of top 25 37 blogs in GIS and cartography, so here is my two cents’ worth:

1. Instruments like Alexa and Technorati are blunt, and measure specific things; extrapolate them into a statement about quality or popularity at your own risk.
2. This is comparing apples and oranges. Really, someone mainly interested in the geospatial industry is going to be much more interested in All Points Blog than Strange Maps, whereas Strange Maps’s popularity transcends the field, and gets readers who wouldn’t be the slightest bit interested in the geospatial industry’s inside baseball. Rinse and repeat with your own favourite blogs, and your own favourite niches.
3. The list is English-only, and in this field, that’s a mistake. One of the best map blogs, period, is La Cartoteca, and I can say that with confidence even though I don’t speak (or read) Spanish. There are lots of blogs about maps in French, German, Spanish and other languages, and some of them are fantastic.
4. There are plenty of general-interest blogs that talk about maps from time to time; add their Technorati rankings to the mix, and like O’Reilly Radar, which really shouldn’t be number one, they’ll displace the rest of us mapheads.
5. Ranking blogs sucks. QED.