With KDE 4.9 having been available for one month now, the release schedule for the next major release has been finalized. KDE 4.10 is scheduled to be released on 23 January of 2013. The schedule isn't exactly a surprise given the KDE six-month rotation for major releases.
Leading up to the KDE 4.10 release will be see a soft feature freeze on 25 October, a soft message/API and hard feature freeze on 8 November, the first beta release on 21 November, the first release candidate on 19 December, and then the final release on 23 January. There's also some other development milestones intermixed between those main goals.
For full details on this next major release of the KDE SC Desktop Environment, see techbase.kde.org.
KDE 4.10 features are tentatively being talked about on this KDE Techbase page.