Some people still ask me from time to time when I'll upload Battle for Wesnoth 1.8. My usual answer is that it's there already since before the official announce went out in the wesnoth-1.8 package.
The longer answer which also answers Why the name change? goes like this: People asked for a way to be able to install different branches side-by-side so that they can keep the old stable branch around for finishing started campaigns there while still being able to play with their friends multiplayer games using the new stable branch. Also people using the development version wanted to not having to get rid of the stable version just to use the development branch.
So there it is! Enjoy! There though is still something missing though, and that's why the question where the 1.8 version of Wesnoth is still pops up: There is no transitional/meta package yet. This requires a bit more work including adding alternative handling (so one can still run wesnoth and not have to use the versioned wesnoth-1.8 binary name) and for that some dpkg-divert magic about the historical unversioned wesnoth packages.
Given that my release is requesting quite some support overhead I can't tell yet when these things will be done, but a similarly related support contract will run out by the end of the month so potential I'll be able to find some time next month to finish this for good. If you want to have it done earlier or feel like helping out, feel free to send in patches after talking with me about the fineprints and potential approaches. Thanks in advance!