Having worked in a distributed team for 5 years (as part of CodeSourcery and now Mentor Graphics) which has a one-week in-person annual meeting every year, I would certainly dispute the idea that such things are "antiquated and inefficient." The critical stuff happens in the interstices around the formal meetings, and you can't exactly go out to a restaurant and chat over dinner on Google+.
On the other hand, such meetings are pretty expensive and require a lot of planning.