Shadow of the Hegemon - Orson Scott Card
This is a sequel to Ender's Shadow, and explores the political and military struggles that take place on Earth after the war with the Formics. Peter Wiggin, Ender's older brother, features more heavily in this book, but most of the book follows Bean. Besides them, there are also several other Battle School grads.
The part I enjoyed least about the book is that there just seem to be too many geniuses. All of the Battle School grads are brilliant strategists, and their conversations get a little tedious—instead of seeing characters try to figure things out, you basically have a bunch of them involved in sitting around explaining why things are happening the way they are, and almost nothing is unexpected. Even Peter's parents turn out to be smarter than expected. I can only think of perhaps two instances where any character is caught off-guard.
That said, it's also fascinating to read about how things played out on Earth after Ender left: in the original Ender series, he leaves for distant galaxies soon after the end of the war, and so everything else that takes place in the series is thousands of years later. Card decided to go back and fill in some of the gaps, and he's done a good job of showing how the existing characters played their roles in the inevitable power struggles.
On a side note, in Card's Afterword, he mentions that one of the most influential books for Shadow of the Hegemon was Guns, Germs and Steel, a book about the rise and fall of human societies which has been on my list for some time. (And in fact, I had it checked out of the library at the same time but haven't gotten very far yet.)