Actually just to nitpick I would classify Battlestar Galactica as a re-imagining of the original series since they took the basic concept and characters from the original and just changed around the plot. A reboot IMO would be to start the franchise over from scratch and use only the simple themes that Star Trek would use. The upcoming movie could be seen as an attempt to restart the franchise from the start using new updated motion picture visual effects, new actors, etc. This is how I categorize the terms.
The books are a example that we can move on from Post Nemesis, Post DS9, Post Endgame, etc and still tell good and interesting stories. Reboots are fine, but normally come from writers running out of ideas for new stories IMO.