Interesting link via Seth Godin, author Steven Johnson, has analysed his own work, and a few others, using Amazon text stats to measure the average number of words per sentence, and average number or syllables per word, for several books.
He's plotted the results against other authors. What he's found is that each author writes in the same style for most of their books, and it seems, the higher selling authors use less words per sentence and less complex words.
That's probably true of bloggers as well. Certainly the ones I read. And my reading choice has always been contemporary work with short sentences and short words!