FOSS4G 2013 Lessons Learned
This year we had a "supporter" sponsorship level, which was aimed at those companies who would not want a stand, but would want some minor branding on the website and at the event. This was very popular and we'd recommend it to future organisers.
A submission notification should be provided within the service for submitting abstract, workshop, etc. An automatic reply mail would do the trick. We did have a section on the web page leading to the submission section that said people wouldn't receive confirmation, but either they missed this or wanted to check anyway, so it ended up causing more work.
We've used Lanyrd to publicise the event alongside the "usual" channels, and also Eventbrite for dealing with the free hackathon registration.
Paper Selection Methodology
The OSGeo community is very passionate about openness, so the methodology needs to be made as explicit and open as possible. Where additional filtering on top of the community vote is required (which it invariably is) then this needs to be explained clearly in the wiki. There probably ought to be an established methodology for doing this, which should be recorded in the FOSS4G Cookbook.
Workshops are limited by the size specified by the author, and also the size of the rooms available in the venue. There's a juggling act to do when assigning workshops to rooms (and hence knowing the maximum number of people who can book onto it), and it's also important to consider the expected popularity of each workshop. Expect to have to move some around when bookings come in.
Ensure the program is out before the end of the early bird deadline as people may wish to choose which day(s) they attend on the basis of the program.