It seems that blogs to which I post less frequently get indexed far slower than ones that get more of my attention. The frequented blogs also get to slide with smaller posts as well, sometimes even a single sentence gets indexed.
That falls right in line with my Orange County wedding photographers posts.
An SEO expert would say that 100 to 300 words is necessary for a post, and generally, I would promote that, but sometimes, fewer words is better. If you think not, watch political news for a while.