The full list of the other speakers at Caixa Forum not yet updated on the official site

Carmen Platero: Cinema and videogames.
Valentina Nisi: 'Weirdview'.
Daniel Garrido: Interactive Fiction.
Olli Leino: Post-narrative Possibilities in Computer Games
Geoffrey Thomas: Storybeat.
Dominic Arsenault: 'Dynamic range'
David Crawford: SMS
Lourdes Cilleruelo: Visual art, internet and new narratives.
Marina Zerbarini: 'Eveline'
Conor McGarrigle: 'Cyclops' and 'Proteus'.
Miguel Sicart: The ethics of design in ergodic art.
Calin Man: 'Golden Virus'

There's an interesting online conversation between the curators about the origin of the symposium and the term "metanarratives" on the symposium blog.