In case you missed the recent launch announcement, CPAN Testers 2.0 is live and the email mailing list used to submit CT 1.0 reports will be shut down around August 31, 2010. I consider this the start of the "public beta" period for CT 2.0. Most of the beta testers so far have been experienced testers, but I'm sure we'll see lots of new questions and issues to fix as more people start switching over to CT 2.0 before the deadline.
If you are already a CPAN Tester, a "profile file" has been pre-generated for you and you should submit a request that it be emailed to you. This pre-generated profile will identify your new CT 2.0 reports in a way that will make it easier to link them to the CT 1.0 old reports as those are converted.
If you are new to CPAN Testing, you will need to generate a profile file. Install Metabase::Fact and then run the metabase-profile program from the command line. It will prompt you to provide some information and output a profile file. The first time you use this profile file to submit a report, your profile will be automatically registered on the CT 2.0 server.
While the CT 2.0 server has launched, the clients that submit reports are, for now, the same ones used for CT 1.0 -- either CPAN::Reporter or CPANPLUS (or one of the smoke frameworks written for them like minismokebox or CPAN::Reporter::Smoker). The transport framework originally intended for email gets hijacked to send reports via http to CT 2.0 instead.
To send reports to CT 2.0, you will need to install the Test::Reporter::Transport::Metabase module and then configure your client to use that transport instead of the default one. Instructions are available on the CPAN Testers Wiki. While the docs are a bit sparse as I write this, I expect they will continue to evolve and improve as more people contribute to them.
If you're really stuck, please check the FAQ or ask for help on the CPAN Testers Discuss mailing list. If you are a CPAN Tester, I highly recommend joining the list to keep up on the latest issues and solutions in the migration to CT 2.0. If you do ask for help, please be sure to include the version number of all the relevant testing modules you're using along with your perl -V output.
Another good place to go for quick questions is the #cpantesters-discuss channel on irc.perl.org.