well, on my mind, A1GP is the better series. If I remember the crowds at Zandvoort last weekend standing in the pouring rain, waiting for the race, and then the Prime Minister, saying the words "gentlemen start your engins" it was realy great by the fans at the track. Superleague Formula has a facinating Qualifying Format, but it only has got some local relevances. For Germans it is only attractive to those, who like Borussia Dortmund, or another froreign club, somehow. It is nothing nationwide, like A1GP is. I think A1GP will survive with their concept. Superleague Formula refering to what tinvek said, missed the time to start, sothat they could be "the" Formula class, wich introduced the "Drivers are not driving to crown a driver's champion but a team's champion"-concept.
To build up more contact to motorsport fans, Superleague Formula should really think of having street races in some of the team's city's. With Vallelunga they do something in that direction, as Vallelunga is quiet near to Rome. But Jerez is not really close to Madrid, and Estoril is closer to Lisboa. Corinthians-, Flamengo- and Beijin-Fans have about NO contact with their motorsports teams. They could use the Autodromo Carlos Pace in Interlagos and the Beijin-street-circuit... I think a new series should firstly get fans at track and then fans at the television screen. And in another point i have to agree with tinvek: They should really use the summer season. Football/Soccer Fans are feeling a depression during the summermonths, when there is no continental championship, exept you're living in Russia and having a March - November season. Maybe (a big maybe) they should have something like a show race with some of the team members. I'm thinking of production cars of a certain class, with roll cage. A bit like the celebraty race at the Grand Prix of Long Beach.
Let's see what the future will bring.