Comment 2 for bug 1507803

I'm surprised you've run into this issue, I can't find anything that depends upon the ttf-mscorefonts-installer package:

$ apt-rdepends --reverse ttf-mscorefonts-installer
Reading package lists... Done
Building dependency tree
Reading state information... Done
ttf-mscorefonts-installer

If this is correct you can probably just use apt pinning to forbid it: http://askubuntu.com/a/76075/33812

The apt pinning is probably easier than using equivs, but that really should work if something else Depends: upon the MS TTFs.

Thanks