It only shows on some searches at present, but here is a good one: Museums London
In case this disappears or Google changes it into a neon sign with dancing girls, then here's what it currently looks like:

Interesting eh? Now in this example you can still see some organic results, but other searches show sponsor ads, meaning organic results show below the fold, which is an increasing and worrying trend.
Each result in the "Carousel" isn't a link back to the relevant website as you might expect, but a refined Google search, that then allows Google to populate info panel on the right hand side of the search results, and hopefully give relevant results in the search results (assuming no sponsor ads).
Interesting developments, and I think this is just the tip of the iceberg.
Anyone rolling out a new website now should seriously looking at structured data mark up, and if you're webdesigner doesn't understand it, find one who does!






