Mojang is having a semi-public discussion on Saturday at 2000 CEST (4am AEST on Sunday, 7pm GMT Saturday) about the planned Minecraft API. This is part of the planning process for various changes to Minecraft which will make it easier for mod developers to integrate their mods with vanilla Minecraft. The lead Mojang employees working on this are the 4 guys they employed who are also the backbone of the Bukkit development team, led by EvilSeph.
This meeting will be on the Esper IRC network ( irc.esper.net) in the channel #minecraftdev. They are going to restrict who can talk but hope to have representatives from a variety of major mods, including the rivals to Bukkit. Logs of the conversations will probably be released after the discussion.