Personally I think public institutions should be ALL or NOTHING. If a public transit organization want to put up "Merry Christmas" then they should also have "Happy Hanukkah" and "Ramadan Kareem" at the appropriate time of year.
Tony Clement recently sent out a memo to all government departments that federal employees were allowed to decorate their offices with whatever decorations that are traditions to their faith, whatever that faith may be. So for Festivus (which is secular) I have my Festivus Pole. And for Holiday, I have an ornamental FSM and posters outside my office like this:
If Clement had said "Employees are allowed Christmas decorations and other faiths are not allowed decorating" I think there would be calls of discrimination.
And just because "it's tradition" or "Canada was built on Christian values" doesn't mean it has to stay that way. We were progressive and inclusive on things like gay marriage, I think we should strive to be inclusive of people of other religions too.
As for having the statutory holiday on the 25th, I think that is wrong as well. I think employees should be given 8 statutory days off in any given year and they can choose when they want to take them. The Muslims that I work with here take vacation days for the Eids. The one Jewish fellow on the team takes off days during Hanukkah. They would prefer to be able to work the current statutory holidays and use those as vacation days at other times during the year, but it's not allowed.