Check-inThere are two ways to get packages into openSUSE 12.2 right now: The one way is to create a maintenance request against openSUSE 12.2 - the same way it's done for released distributions. The other way is a submission to factory, the release team reviews all submissions for Factory and decides which ones to take for 12.2 as well. So, if you really want your change in 12.2, you better state it as part of the submit message and write an entry for changes that makes the release team want the change.
PublishingThe openSUSE maintenance team likes to get everything - but the packages that went in via maintenancerequests as well as the packages that went in via Factory - out as updates. So, if you have the 12.2 and the 12.2-non-oss repositorires (from http://download.opensuse.org/update/ as repositories, you'll stay up to date.
Once RC2 is published, a full tree gets published together with new ISOs.
Note, that we now split the update repository to have a separate update repository for packages that are not Open Source.
Update 2012-07-14: During an installation of openSUSE 12.2 RC1, you get already the path of the 12.2 repositories. If you don't have them, enter directly as repository http://download.opensuse.org/distribution/12.2/repo/oss/ and http://download.opensuse.org/distribution/12.2/repo/non-oss/. The links are redirects right now and point to RC1 - and will be updated with future releases.