Without Britain and it's lobbying for big finance and wall street, we surely will see more financial regulation. It is something which could even make the EU look good in the eyes of the people now, because most have wanted this for a long time. This would mean the UK (or probably just Britain at this point) would lose a major advantage to international finance. You will still need a headquarter inside of the EU and it can't be London anymore. Frankfurt just waited for this, they talked about this for weeks. Probably the only ones in Germany welcoming a Brexit.
Yeah, I bet they have... pretty worrying considering I work for an Insurance company based in the City. I imagine Frankfurt will seize the opportunity in full... they'll be a feck ton of investment coming there way over the next 2 years.
We've basically just shot one of our biggest and best industries in the arm.