Can I sync Firefox bookmarks with Android?

I believe Fennec (Firefox mobile) will have this feature, but it is currently only in alpha. You can get a copy of the alpha here. Note that you'll need about 40mb+ of internal storage space free to install it.

I don't see a FireFox extension that bring bookmarks to your phone permanently. There are a few suggestions in this question but they are designed more for sending links on a one-time basis. Getting the Del.icio.us FireFox add-on and the Del.icio.us add-on for the Android dolphin browser might be the best bet. (I knew I saw this somewhere on here... props to this answer which mentions Del.icio.us for Android.)