Hi Gianluca,

you can get much of that info from the Barcelona - Maemo Long Weekend wiki page:

http://wiki.maemo.org/Maemo-Barcelona_Long_Weekend

particulary from the Agenda.

The topics would be more or less the same.
Have a look at *our* wiki page here : http://wiki.maemo.org/Maemo-Italian_Long_Weekend Section: Preferred Topics

As for the number of people I think it much depends on the location, but I am confident it will be close to how many there were at the Barcelona event. That is around 100 people or more.

Also you can have a look at the youtube videos made in Barcelona:
http://www.youtube.com/user/nokiadevforum