I want to do something far better. There's loads of conferences about Bitcoin now so I think it's better to do an event that contributes something new to the discussion rather than the same as what's happening in New York, Atlanta, San Jose, Argentina, Amsterdam, France, Germany and London 3 times. More info after September. Location will probably be Barcelona or Italy.
Why is the location going to be changed? This looked like it was prepared in 95% (
http://web.archive.org/web/20130424024013/http://unsystem.net/) and I really wanted to attend (I've sent an email about the tickets a few months ago but haven't received a response), Vienna is also closer to where I live now, I could drive by car.
If you're still deciding about the location I can recommend a good venue in central Poland, PM me if you're interested.