It's tough, isnt it, to keep a piece of software small and perfectly formed, features seem to just sprout
This is just for information - I was looking into the matter for other reasons recently, and it might be useful: both gmail and facebook allow export of birthdays, but only as ical. If you are looking at one off import this might be a useful option to consider.
I would say that is my biggest problem with birthdays: you seem to copy/enter them over and over. Phone, email client, online tool, paper diary. And as a result you dont copy all of them, losing some behind that you might regret later (especially if you forget you hadnt copied everything and reformat the machine) and never have all of them anywhere. My side project was looking into "master data" for contacts but especially birthdays, and how to import/export/convert so i can have them on my phone, online etc. and not miss a birthday whether I am home or travelling