The fact that handset number 5, the Sony-Ericsson K810, does not exist (outside the confines of student imagination) also makes me question the figures a lot, though presumably they meant W810 and just didn't bother to proof-read or don't know much about phones.
The presence of the 6620 suggests we're looking mainly at the US market here, the rest are all very new phones except the 6600 (lovely phone for development) and the ubiquitous chav phone.
All this leads me to one conclusion. If this really represents MobileRated's top 10 phones downloading their games, they are only being checked out by advertising and marketing execs owning the newest / most fashionable top-end phones. This is the only group I have seen who really do all have handsets like this, so maybe this is telling us something - just not what they wanted to reveal ;) Maybe we could see some more quantitive download figures?
UPDATE: finally found that very useful Bango popular handsets page - a nice public counterweight to the suggestion that people who download mobile games only have the absolute latest and greatest handsets. Real people downloading content appear to use a mixture of phones from across the spectrum, so MobileRated appear to be missing out on a lot of their target audience right now. It remains to be seen whether people reading their press release will realise what they're really being told.