Without even doing daily posts, I'm seeing some blogs I've setup hitting a higher PR in a few months ... lots higher than sites that went up even 4-5 years ago. Using additional filler that is keyword rich for the blog niche will certainly help as far as the SE goes of course. I actually see blog sites as becoming more of the longterm "freesite", especially as category sections get indexed. From that perspective, the showing of one or two pics of a particular gallery with a link to the sponsor's site as opposed to publishing 2 pages of galleries would really diminish the free pic saturation.