Pre-ApacheCon meetups work for me!
We were about 25 people at the meetup, some of them coming just for the day (which is fairly easy from most parts of Europe due to good flight connections to Amsterdam), the content was improvised on the spot in unconference mode, with audience turning into presenters as needed. Some slides are available on slideshare. My own slides were created while listening to other presentations, so they might not be as polished as you'd expect...but they worked!
I think having those meetups right before ApacheCon is a good thing - the pre-conference hackathon has somewhat lost its interest with the growing number of projects (we need a K, we need a Z ;-), meaning that there's not much interest in people from all projects getting together to work, it is more small groups of projects that get together.
In Amsterdam, the ripoff (my personal opinion) prices charged by the Moevenpick hotel for most everything caused the meetups to happen in a nearby building, I don't think that's really a problem as people can meet during the conference days anyway. Having meetups colocated with the conference would be better, but it's not a requirement in my opinion.
What do you think, did you attend a meetup? Do you think pre-conference meetups should become an ApacheCon tradition?