Embassytown is nominated for a Nebula for 2011, and I think it's the one to beat. Here's why:
China Mieville's novels are great examples of "idea" SF. But not just any ideas, or explorations of technology--Mieville goes after philosophy. In The City and The City he very purely explored ideas of place, and how one knows where one belongs. Embassytown has more of the tropes of SF--it's set on an alien planet, with alien beings and technology--but it's every bit as idea driven. The core idea being one of semiotics.
A perennial problem in philosophy is that of reference, significance and anaphora--how we come to associate things in the world with our language. A pretty tough idea to convey as problematic, but Mieville will give you an introduction with his Ariekenes, a race where language does not signify and there is no anaphora. Ariekenes speak Language, with two mouths (which makes for some interesting typography), and the words are wired directly into their nervous systems. They construct "similes" out of living humans and other things to give substance to comparisons, their thinking tools. The central trouble comes when they are sent an Ambassador (pair of humans) from Earth that speaks Language in such a way that they become addicted to it.
It takes a lot of work for Mieville to get this across, but it comes clear as the drama unfolds. He has fun with other words--he introduces the term "floaking", for a certain sort of taking advantage of what one knows and being acceptably productive without working hard. It's kind of unattractive or it would make its way into the vernacular.
The human characters are harder to appreciate, though they are worthwhile. The protagonist, Avice Benner Cho, is a starship navigator and accomplished floaker, kind of drifting until the crisis peaks in Embassytown. She proves acceptably sympathetic to drive the plot.
It took a bit for the book to get going, but it's definitely worth the work. You will think differently after you read it, just as the Ariekenes do. Read it for fun, and particularly appreciate it if you enjoy thinking about what words do. We haven't had this much fun with semiotics since The Name of the Rose. I give it 4 stars.