This article is from the Bee Gees FAQ, by David Garcia firstname.lastname@example.org with numerous contributions by others.
Not for a very long time, from the sound of things.
However, if you're looking for an "unplugged" album in
particular, the mini-CD of the "Storytellers" performance may be
of interest to you. It was, at one point, available as an add-on
to the "Still Waters" CD at Target stores in the US. Perhaps
these songs may appear in other forms elsewhere in the future;
then again, maybe not.
So far, the closest they've come to a Christmas album has
been a rare performance of "Silent Night" on an old fan club
release some years back. The requests by fans for a Christmas
album have been many, but the brothers have maintained that they
just aren't into Christmas albums.
On the other hand, we now have the track "Miracles Happen"
on the "Still Waters" CD. This song was originally written for
the movie remake of "Miracle on 34th Street". Not exactly "Have
a Holly Jolly Christmas with the Bee Gees", but it's a start,