Last year's PyCon was really wonderful, my hats off to the team and volunteers behind it because it was a really special experience. I'm excited about doing it again this year! I have no clue how I am going to manage 6 tracks of epic talks though...
Because; 2014 and 2015 are happening in Montreal CA rather than a larger US venue. The reason why we can do this in 2013 is due to, as they say, "location, location, location". We have the projected attendance to back the expansion this year, but I sincerely doubt we will in other locations and venues.
I'd rather hedge now, then set the expectations it will "always be this big" - because honestly, I don't think PyCon should continue to expand, and that this should be a one time thing for the conference.
Long term; the PSF and PyCon itself will end up pushing more and more local / regional conferences and capping attendance at the 2500 attendee level intentionally.
tl;dr: Continued unbounded growth in attendance, number of tracks, etc will dilute the conference and take it in a direction most within the community and the foundation do not wish it to go in.
Perhaps OT, but I attended a YAPC in Montreal. What a fantastic city to visit, and the conference fit in very well. If you (speaking generally) can and your housing option permits, I'd recommend taking a couple of extra days to kick around town.
It would probably look cool but I'm not sure it's functional. It would just be 6 TV's showing a person standing on stage. Even in bars where they show 10 football games at once, they only play the audio of one of them, which is the part that matters for a conference talk.
From where? I have no idea what this takes and what it would cost, but if someone does it, I will gladly publicize it on the blog, twitter, relevant mailing lists local to the flight, etc.
Contact a company like Express Jet, I know they (at least used to) rent out whole CRJs (50 seaters) for private events. If you can fill up every seat, it comes out to a cheaper price per seat than normal airline seats.