Since Subeta keeps track of user birthdays anyway and denotes the user with that tiny cake icon... how hard would it be to generate that into the friend feed as well? It would be nice to know when it is one of your friends' birthdays.

You can make a notepad widget yourself for that.

It might be a bit hard since (when the site is actually WORKING) users can opt out of having the icon show up for them.

true, they would have the option to opt out of it, just as we could opt out of having it show up on our friend feed.

How does one create a widget that will pull up subeta friends' birthdays for me without my having to ask each person when their birthday is?

Ask for their birthday. It doesn't hurt

Personally, I don't really want developer time used on that when they could be working on wardrobe glitches and stuff.

I wouldn't mind this as a feature eventually, but if and only if for those that have the icon turned off their name didn't show up on the list. I can understand people wanting their privacy.