Should a common-law marriage be celebrated?

More specifically, consider this hypothetical situation:

A loving, committed couple is not interested in getting married yet (for whatever reason), but plan on getting married eventually. The day of their Nth Anniversary of Living Together (depending on state) comes along, and they realize they are now in a common-law marriage.

Is this cause for celebration? Could they have a party with friends to celebrate their common-law marriage, despite there being no ceremony for the “marriage”?

How do you feel about the celebration of common-law marriage?