On balance, I think I'm against the idea.
As far as openness is concerned, those who have the inclination to observe the legal process have unrestricted access to the public galleries. If we open this sort of thing up to the media, then all sorts of additional political agendas will come into play.
My immediate reaction is that the majority of people (sad but true) have no real desire to partake in discussion about this sort of thing and by inviting cameras into the courtroom the majority of people (who don't care especially..) will be fed a warped view of proceedings and make ill-advised and media-biased judgements about cases.
I think it would be very unhelpful.