I plan to stay in sync with the Ubuntu release cycle as much as possible (see https://wiki.ubuntu.com/LucidReleaseSchedule). So, next release should be near the January 14th.
The real first release of lubuntu should be for Lucid (10.04), in six months. To prepare it, I began to write 3 specifications  about the future Lubuntu, to hold discussion about some aspects of it. I hope to be at the Ubuntu UDS  to work on them. Feel free to contribute to them (with constructive arguments, not troll please :)) Nothing is decided, and help in various aspects to make Lubuntu 10.04 rocking, will be very appreciate :)  https://blueprints.launchpad.net/ubuntu/+spec/lubuntu-lucid-artwork https://blueprints.launchpad.net/ubuntu/+spec/lubuntu-lucid-default-applications https://blueprints.launchpad.net/ubuntu/+spec/lubuntu-lucid-packaging-policy  https://wiki.ubuntu.com/UDS