Hmm, there are a few parts of this which I can foresee being reasonably important for us.

Image Search landing page quality signals -
I've found improving page quality to be a little bit tricky when it comes to WP. There's only so much tweaking you can do. Optimized images, fewer links, adequate caching and original text are possibly the only things we can actually without falling into a pit of coding.

Better spam detection in Image Search -
Although this is a little bit vague, I'm thinking this relates to image tags and their relevance to the post. Whether you're using a collage or individual pics, I think it's wise to label them with something relevant and not simply leave the existing name in place, or have nothing to describe them at all. Perhaps it might be time to start using that large box for some lengthy descriptive text?

More accurate byline dates -
This could actually help with duplicate content. If people are stealing content from your site and being crawled before you, they can get credit for that work while you're left to be labeled as the duplicate. It's still unlikely they'll actually have a way to know other than the through publish and crawl dates though.

Improvements to image size signal -
Does this mean that sites with the original version will gain more traffic than those using a re-sized version? It could be time to either stick to the original image size or create even larger collages.