It would appear that the new upstream release of libapache2-mod-perl2 has been relicensed; from the ASL 1.1 to the ASL 2.0. As has already been discussed, the ASL (both 1.1 and 2.0) and GPL are incompatible (at least, the FSF claims they are). What has previously been used w/ modperl (1 and 2, under the ASL 1.1) has been perl's Artistic license. The question is, does the change to ASL 2.0 introduce any incompatibilities with the Artistic license? Is it safe to upgrade libapache2-mod-perl2 to the latest version?
As a side note, there was a d-l thread in Feb. about the Apache group and the FSF talking about resolving their disagreement regarding the patent termination clause in the ASL 2.0 rendering both licenses incompatible. Does anyone know if an agreement has been reached?