Besides the main speakers, smaller keynotes will be held in the developers' rooms, called Mozilla, Jabber, Gnome, GNU Classpath, Ada, openSUSE, Debian, Calibre, Linux on Laptops, and others. Take your pick.
Related items:
fosdem.org
Fosdem 2006
Free and Open Source Developers' Conference
A conference on the latest in open source development, focusing on the themes desktop (openoffice.org), development (source management tools such as darcs and valgrind), security (on the ClamAV anti-virus and others), systems (Ian Pratt on Xen, and DTrace), voice over IP (on Asterisk, Speex) and web 2.0 development (Dojo Toolkit, RIFE, Selenium).