The choice of sessions Cynthia mentioned will help the organizers planning the size of rooms. It can be found here:
http://www.tdwg.org/conference2009/program/session-selector/
There is no conflict between the three BDI sessions. The session description on
http://www.tdwg.org/conference2009/program/working-sessions/
is a bit brief and outdated, but we have no means to update it. Thus, for the BDI II and III sessions (14:30-17:00 on Tuesday) we have an internal planning page:
http://wiki.tdwg.org/twiki/bin/view/SDD/BDIWorkingGroupSession2009
This list includes the "Visual and textual standards for taxonomic identification" session, We (Hagedorn, Grard, Bonnet) organize the two sessions together. Contributions to the planning and proposals for further topics are welcome.
Gregor