French guy in Austria reporting.
One quick thing I read there about France, Le Pen is no way in hell going to be elected anytime soon. Our republican party (conservative right wing, ex UMP, the party that ruled between 1995 and 2012) will be elected in 2017, it is pretty much set in stone, the left wing party is dead with all the laws they made, especially the work law (a lot of them were "imposed" by the EU). Unless there's another terrorist attack or so and then Le pen can maybe find a way to be ellected. But then she will need to win the Parliament election. And I don't think that France is wanting to leave the EU. Btw if France leaves, France is dead, the EU is dead and some African country are exposed (those with the Franc CFA, a currency controlled by France, indexed on the euro right now)...
Also, Switzerland never gave a fuck about the EU anyway, I don't understand why people are speaking about it.
One on the thing what will be impacted by the Brexit will be Universities. With Brittain out of the EU, European student will pay the crazy prices to study in England. To give some comparison, the tuition fee for master in France cost roughly 500€ in a classic university whereas in England it is at least then times this price. The mobility of student itself may be impacted. For European PhD / researcher, it may means that England won't be attractive. The other way around, it may make moving around the UE harder for English student/phD/researcher. If the current border system remains, then it shouldn't change much but then I am an outsider so I am not sure if UK wants the stay with the current border system. Anyway, it gives a "you're not welcome here" impression to European students. I have some friends that went to study/work in the UK or were planning to do so, there are not that convinced anymore. Some are planning to come back one, if there're still in the UK.
I also have UK friends that are eligible to Irish nationality and they will apply to be able to easily travel in Europe for their PhD. It may be very marginal, I don't know if a lot of people will do it.
For companies wanting access to the European Market, it means that they'll need to relocate on the continent and leave the UK. Relocate where ? Probably Germany, France or Benelux countries so for EU it doesn't change anything and for those countries this is a positive point.
I am not sure that UK leaving will do anything to EU other than some countries asking for referendum, UK was not that deeply connected to the EU anyway. And I'm pretty sure that the EU will want to punish UK for leaving EU, and so, I expect the negotiation between UK and EU to be difficult.
The question I have is what are the laws that are imposed by the EU that UK people oppose ? Most of the law imposed to France that people oppose (like the current work law, that gives a LOT of strike and protest) are law influenced heavy by neo-liberalism and, if I am not wrong, UK is a strong defender of neo-liberalism in the EU. As someone deeply opposed to neo-liberalism, I think that EU is better with one less defendants of this toxic stuff as it means that laws that remove worker protection will have less support at the European level.
So in the end, my opinion of the subject from an exterior point of view is that, it shouldn't have a negative impact on the EU (or at least not on France) but it may be bad for UK depending of the negotiation (and if there is independence for Scottland/North Ireland, it will weaken the UK but the EU is not impacted as UK won't be part of the EU any more).