Dual-license GPLv2+/LGPLv3+?

[Simon Josefsson]

Hi!  The GnuTLS project is changing to support a flexible crypto backend
interface, and we'd like to recommend people to use Nettle as it has
some nicer properties regarding thread safety and setuid.  Nettle
depends on GMP for bignum.  However, it was recently pointed out in
http://www.bebt.de/blog/debian/archives/2011/02/20/T13_14_34/index.html
that there are many GPLv2-only projects that is using GnuTLS, which
would not be able to use GnuTLS linking to GMP.  It has been discussed
on the gnu-prog-discuss (IIRC) to dual-license some libraries under a
GPLv2+/LGPLv3+ license to avoid this problem.  Could this be a solution
here?  Any other thoughts on this?  Since all of GnuTLS, Nettle and GMP
are GNU projects, we could also ask the FSF for guidance on this.

/Simon