Many in the working-class would react like "good for them, wish we had a referendum!" whereas the young educated types would instinctively dislike it, especially as it may (emphasis on the "may") complicate coming over to the UK. In reality not much will change, at least for the first few years as everyone gets a feel for the new status.
The business chiefs aren't happy with a Brexit...they're broadly in league with what the IMF have been saying: that economically it's risky. Personally the IMF report read like pro-business propaganda, even scare-mongering at times. There's certain vested interests in a Bremain, things like inter-trade with other EU countries being relatively simple to do. Britain being in the EU with such niceties hasn't helped certain issues like too-high rents/houseprices, domination of the temping sector for young workers and general job-instability. These are problems in Germany too.
These issues will remain after a Brexit so the man on the street won't really tell the difference in that respect. I guess the best argument the pro-business Germans have is that a Brexit may reduce inter-trade, meaning a reduction in British projects, meaning potentially less jobs.
A clever post-Brexit policy shouldn't present a real problem to the man on the street, be they German or British. Switzerland and Norway are doing fine by limiting their obligations to the EU without being a full part of it.
