While Android continues to get better about making its UI look gorgeous, there are still plenty of trends that have yet to be standardized in any meaningful way. Of course, part of that may be because they don't need to be. After all, Google doesn't want every app in the world to use the Google Now-style card view (though, so far, Google+, Search, and Currents are already among those that find inspiration from them). This leaves implementation up to developers, like those featured over at AndroidViews. Here are just a few samples of their work:
As you can see, it's not just the cards UI. In the center above, you see a framework for a ribbon menu, like the one in the Google+ app, which is becoming so very common these days (appearing now in Facebook, Spotify, Currents, Astro, Steam, and a ton more). Or, on the right, the Slide Expandable ListView, which offers a Spotify-like slide out menu for contextually appropriate options.
All of the interface samples you see here and on their site are completely open source. You can download any of them to import into your app, and each one has a place on either GitHub, Google Code, or BitBucket in case you'd like to contribute something back to the community.
None of these will make your UI for you, but they should help quite a bit. Head on over to the site to take a look at more downloadable interface aids. The site seems to be updating semi-regularly, and is also accepting submissions. So, if you happen to be a designer that would like to get some of your work featured, you should definitely check it out, too.