St. Patrick's Day is a great excuse for a party and can provide great wedding inspiration. Green is the obvious way to go as this board from Rustic Wedding Chic demonstrates, but there are other options as well.
If you're of Irish decent you'll want to think beyond the green or orange color scheme. For example, you might consider incorporating Irish lace in to your wedding dress for a romantic and culturally appropriate touch.
For entertainment, of course there are bagpipers, but consider adding something a little out there and look in to an Irish dance performance.
Corned beef and cabbage might not be the wedding dinner you have in mind but why not incorporate a fun touch such as serving Guinness or Irish Soda Bread as in this picture from Equally Wed.