I don't know of any other pgp developers that have even started on the
ElGamal side, I have asked on pgp-dev.
I have Elgamal in cryptlib (modulo keygen at the moment), but as you say,
nobody outside the US cares about it. I added Elgamal mainly because some
people I know in the US asked for it and it wasn't that much work (again,
modulo the keygen which is a real bastard to do quickly and efficiently). In
NZ and Australia neither RSA nor IDEA are patented, so everyone just sticks
with that they know from PGP 2.x.
I agree with Ian that RSA should be left in for non-US implementors who don't
have to worry about patents. For us the concern is getting people to use the
implementation, people have heard of, and trust, RSA, people can sometimes be
persuaded to use DSA, but noone outside the crypto/security community has ever
heard of Elgamal, and it's going to be a tough job going to someone who barely
knows how to spell RSA and convincing them to use a different algorithm
they've never heard of before.
Peter.