Vonnegut is an author widely known for his mind-blowing novels and sprawling style. In Timequake, he does not disappoint. While not as classic as Slaughterhouse Five, it is still good Vonnegut. (Although, many people state that they like his earlier novels better. It's opinion.)
The author's disconnected and sprawling style really shows - Timequake is more a collection of anecdotes, fictional and real, in no particular order. Some of it is from "Timequake One," the original story that was scrapped. Vonnegut actually references "Timequake One" within "Timequake Two," along with several other short stories that he never published. He credits these to "Kilgore Trout," a sort of alter-ego. (Well, it's complicated.)
One theme of the novel is free will or the lack thereof.
When the universe sends everyone back ten years, everyone on earth is forced to repeat everything over again, exactly the way they did before. They know what is coming, but are unable to do anything about it. Thus, over the course of ten years, people fall to apathy about what they are doing - they no longer have free will. Once the Timequake ends, this "Post-Timequake Apathy" stops everything in its tracks. People have become so used to a lack of free will that once they obtain it, they stop short, not knowing what to do. Cars crash because their drivers don't steer, people fall mid-step, and everything is chaos as everyone stops.
Basically, humans are very prone to letting outside influences make decisions. Once a dictator emerges (in the novel, the universe itself), people will simply fall into step without thinking. This apathy is dangerous.
While not his last novel (God Bless You, Dr. Kevorkian was published in 2000), it certainly wraps up his life. The points he made so eloquently in his other novels all come in at some point, during some anecdote. His experiences with war and family, as well as bitter and biting humor, all come into play. This leads to a more disconnected and unstructured feel than his other works, but it gives more insight into how his insights were formed.
I would recommend this to anyone who appreciates other books by Kurt Vonnegut, Jr., but if you haven't read him at all, you probably would not find much pleasure in it. When I read it for the first time, I couldn't stand it; after I finished Slaughterhouse Five and Cat's Cradle, I reread it and found much more to it than I had originally thought.
(We'll all meet one day at the great clambake in the sky. Ting-a-ling, you son of a bitch! :D )