All the shareholders discounts and information can be found here:
http://corporate.disneylandparis.com/shareholders/shareholders-club/index.xhtml
Just a run-though. You have to purchase at least 5 shares in order to apply for the shareholders club. The price of the shares at the moment are 4.70 Euros. Less than 20 shares will incur a 30 euro fee every 2 years. People who purchase 20 or more shares will be exempt from this fee.
The discounts range from 15% off most restarants, upto 15% off boutiques and shops as well as 15% off Annual Passes. It also allows 10% off any Disney stores within Europe.
One of the exclusive features with the shareholders club is free entrance to Salon Mickey. This is a shareholders-only privelage where you can have pastries, coffee, tea, soft drinks etc free of charge in a nicely decorated room. Actually, Salon Mickey on its own is worht every euro you pay for in shares.