Is it rude to wish non-christian people Happy Easter?

I’ve got a website which has a feature a bit like Fluther’s where every time you log in, a random welcome is shown in the form of “Welcome, username” or “Bond, Username Bond” etc. Would it be rude to non-christians if I changed it to “Happy Easter, username”?

What Jewish, Muslim, Hindu and other religious or national holidays should I mention in order to be fair to all my users?