The big thing here is better image stuff (via @ekzyis). When you click on a image now, it'll go fullscreen rather than resizing in place. It also won't ruin your image quality anymore. I'm running a migration now that will take advantage of this across all of our old content. It should finish before too long.
We made sub-switching more like a filter. Before, switching subs would cause you to navigate to the frontpage of the sub, regardless of what page you were on. Now it doesn't. e.g. if you're on ~meta/recent and select ~bitcoin you'll now go to ~bitcoin/recent rather than ~bitcoin ... I think this is more intuitive but let me know if you feel otherwise.
Notifications got a little slow after the introductions of mutes. I've rewritten some of that so it's as fast or faster than before.
You can now mute saloon @nullcount.
We have a bunch of really cool stuff waiting to be merged. I'm a little behind on PRs but these all should see the light of day next week.