@Mark k. -
Problem is that right now no theme that I know of (haven’t tried 2013 yet) does anything interesting with that information.

IMO this feature suffers from the “options instead of decisions” decease It only looks like the WP implementation is similar to what tumbler do, but in reality tumbler enforces many restrictions on what content can be associate with a format, something that WP doesn’t do, and this restrictions pay off for both users and themers as they both know exactly what content to use and expect for each format.

That all gets fixed with the 3.6 implementation - not the UI per se, but moreso the underlying functionality that standardizes on what content exists, and how content gets stored, for various post format types.

Once that standardization exists, I'm fairly certain you'll see more Themes taking advantage of post formats, and doing interesting things with them.