Werner LEMBERG writes:

 > Is the LaTeX team aware that by choosing `utf8' as an input encoding
 > name, many documents which use Dominique Unruh's utf8.def file no
 > longer compile?  Why hasn't been chosen a different name, say,
 > `utf-8'?

because the agreed solution was to use utf8 for the kernel. from Dominique:

   === 5. Interoperability with ucs.sty

   There are some name clashes with my Unicode package.

   - utf8.def: I accept the fact, that this is the canonical name for
   that file and will rename my inputencoding in favour of the kernel's
   encoding.


 > I consider this a serious compatibility problem which should be fixed
 > ASAP, deserving an intermediate LaTeX release.

no. there is probably some more work to do to make the extended version work
nicely with the kernel one but that is/should happen behind the scenes

frank