I'm planning a trip to Vienna. Since I know German quite well, I didn't foresee any problems... but after reading Wikipedia articles about dialects in Austria, especially about Bairisch dialect, I'm a bit worried. If everyone there speaks Bairisch and not standard German, I wouldn't be able to understand.
So what is the situation like? Should I expect to be able to communicate in standard German (Hochdeutsch) in hostels, shops, railway stations, museums, restaurants and so on? If I start to speak standard German, would I be responded to in standard German, or in dialect?