Selecting a DebConf location hard, and can certainly get intense at times. This is an area where the DebConf team and the Debian project can work to improve our processes. There is a wiki page to collect our thoughts in preparation for a discussion later, as planned during the DebConf&Debian BOF.
First off, there is a time at DebConfN-2 for interested localteams to describe their rough plans. These are videoed, and you can view the events online if you would like: for dc11 at dc9, for dc12 at dc10 .
There has been a nominal deadline of December 31, 20XX-2 for submitting a bid (not finalizing), but this has been bent in the past.
While teams are preparing their bids, they should look at the location checklist. This summarize what past organizers know to look for in a location. There are questions sorted by category and priority.
To organize their information so that people can understand, teams prepare bid documents on the wiki (DC10, DC11, here are the winning bid documents: DC10-New York City, DC11-Banja Luka). These start off by just answering all of the questions in the location checklist, but then get a lot of work to make the pages clear and complete. Anyone can browse the pages and ask questions of the teams anytime.
There are several mini-meetings where teams describe their progress, and organizers and other interested people can ask questions. In these meetings, the channel is not moderated. Questions tend to be about the location checklist criteria related things.
In February/March, there is a big selection meeting. This is the only DebConf meeting where the channel is moderated and only voiced people can speak. The voiced people historically are two moderators who keep things moving, two other past DebConf organizers to ask questions and relay questions from the audience discussion channel. (These facilitators have been self-selected in the past, usually in the minutes leading up to the meeting.) Then, there are two people per location whom are voiced. There is a audience channel for everyone else to discuss, and the moderators/helpers will look there for questions and relay them to the main channel. There have been unvoiced Q&A periods and periods which are designated for relaying questions from the discussion channel.
Teams are rated based on the priority list. There has been a simple point list the last two years, -1 to +1 for each point on that list. For each item, there are debates on how many points each location should get. Points are added up, and a result appears. In the past, this has been a simple arithmetic sum, so all items are weighted the same (despite nominally having different weights). In the case of a tie or close call, there is more discussion. For DC10, there was a tie, and NYC won after opening the meeting to the audience and getting their opinions. I didn't pay enough attention to the DC11 selection process to be able to say how that close call was resolved.
So, there it is. Overall, there is a lot of openness in the process, but the exact rating schemes in the decision meeting could use discussion. The criteria are established, but can be refined each year based on what we learn.
If you would like to comment on how to improve this in the future, please use the selection process wiki page (first person create it). We can follow up with a list discussion after our ideas have been fleshed out.