I've got an idea for an addon or even something that should perhaps exist in the UI by default. When you recieve a party invite, wouldn't it be nice to be able to preview the names of the party members before you accept?
Call me silly but as time passes and you meet a lot of different players on a realm you might run into people which you don't particularly wish to play with again. It's easy to put them on ignore but what do you do if you get a party invite from a guildmate/friend and that person is in the group when you join. Cue awkward silence. If you could see the party members in advance you could spot the person you'd like to avoid and just say no thanks.