Description of problem:
IMHO the Boot Loader page is probably incomprehensible and "frightening"
for most ordinary users, so I suggest it should be hidden by default as
an advanced option (say either as a checkbox on the first page or only appear
when Custom-partitioning say).  If anaconda could do the right thing for
common multi-os cases too that would be fine too, but I'm more worried
about new users doing a single OS install for the first time...