We do a lot of events across our global organization. It's, by far, the number one contributor to MQLs. As you know, there's often a manual element when working with event programs in Marketo - mainly, uploading the list of attendees post-event. Often times, that list isn't provided to our Marketo Ops team several days after the event. But for reporting and attribution purposes, this is causing issues for us since the attendance date stamp is the date that the leads' program status changes from "registered" to "attended" (essentially, the date that the list was uploaded). There's no way to edit this date to reflect the actual date.
If this is an issue for your organization - especially if you do a lot of events - it would be worthwhile to vote up this idea (especially since it's not currently on Marketo's roadmap (event though they "like it")).