Don't get me wrong, I love Facebook Events - it's pretty much the easiest way I know to invite people to things. Pretty much everyone I know is on there, I can add people to the event by browsing/searching for names rather than trying to remember email addresses, co-hosting is easy since I can add someone else as an admin, and I can push the events calendar feed to my Google Calendar so the events have some context. That said, there are some really obvious features that are missing:
- Conflicts - When I get a new event invite, Facebook will display it to me on the homepage. What it won't do is tell me if said event conflicts with other events. This should be something that's really easy to do and is sorely needed because the context of "what else is going on that day" is usually pretty important when figuring out how you respond.
- Scheduling - I'm planning a housewarming party in my new place, and the first day I picked just happened to be a day that no one could come. Event planning this way is often a crapshoot. Wouldn't it be nice if Facebook helped you pick dates based on availability? I mean, I realize this would be limited, but it'd at least give you something to work with.
- Reminders - Self-explanatory and a no-brainer. Pretty much every calendaring system worth it's salt has some kind of reminder feature and I'm constantly perplexed at it's absence here. I can't even get around this using the version of the event in my Google Calendar, because if someone marks the event "private" (which happens a lot) Google can't actually access any details or metadata and therefore can't decorate it with it's own.
- Nagging - I used to run a group on Meetup.com and one of the features I really loved was being able to automagically nag the maybes and not-yet-respondeds. Just once, of course - there's a fine line between reminding people to commit and being an ass sometimes. But this is very necessary for all kinds of reasons. The first is that people often procrastinate and for whatever reason don't respond to the event right away. (I do this all the time.) The second is that if an event organizer is trying to figure out how much space/food/drink/Rockband copies are needed, these people will be especially interested in letting the stragglers know that they need to shit or get off the pot.
- Integration - Imagine if you could manage and respond to Facebook Events directly from the comfort of Outlook, iCal, Google Calendar, or whatever it is you use to manage your daily life. Hell, I'd be happy if they'd just realize the account I'm using to pull data into my Google Calendar is the same email as my Facebook account so that Google can show Facebook events as something other than "busy."