Hmmm.... My son is 6.5 but here are some current interests or ones from last year:

computer games (mazes, puzzles, contraptions, etc.)
science and electronic stuff (snap circuits, science experiments)
Reading (loves fiction and non-fiction if it's about science or math)
building (contraptions, k'nex, zome tools, wedgits, marble mazes, dado cubes...)
Puzzle games (think fun games, sodoku, perplexus, rubiks games, brainteasers)
MATH (anything math related. makes up number games, playing with dice)
Workbooks (sodoku, crosswords, word finds, codebreakers, logic links, etc)
Music (playing on piano, using his Ucreate music to mix stuff up)
Art (magnetic mosaics, intricate design coloring books, origami, painting things)

In spite of all this and lots of other stuff he has to do, sometimes he still doesn't know what to do. He isn't bored really...just not sure what to do and what will keep him interested. When he was 4 we created a list for him that we have posted on the fridge called "things to do when I don't know what to do" When is unsure what to do he is encouraged to look at his list and pick something off of it. It has like 60 things on it so surely he can think of something. And of course it keeps changing as his interests change.