The reason for this release change proposal is to reduce the amount of time between releases and make them simpler so that new features can be delivered to users faster. With KDE striving to always be in a releaseable state, this release proposal could potentially work for KDE SC 4.12 and beyond. Two months would be given for merging new features followed by one month for preparing the release.
More details on this new three-month KDE release proposal can be found at this KDE community page. A BoF will be held next week at KDE's Akademy conference to further discuss this proposal.