I'm surprised it hasn't been mentioned yet...
Mastodon's new album came out yesterday. So far I'm really digging it. Especially the haunting organ intro to "The Czar: Usurper/Escape/Martyr/Spiral." It's hard to quantify exactly how it's different from previous releases, but I do notice more emphasis on melody and a more progressive bent, both of which are Mastodon characteristics I've always wanted to see more of.
If you're a fan of music that doesn't suck, you owe it to yourself to check it out.
Mastodon | Crack The Skye
I've been listening to it a lot, and loving it. I know some people will hate it, because it is a big left turn for them, but it's an incredible, breathtaking album. It really is an album that demands being listened to start to finish uninterrupted, it's not an album you throw on in the background or rock out to in the car. It is an album to space out to. As Bran mentioned in an interview I read, it's a much more "spiritual" album.