It could also be a good idea if only one match is chosen from round 1 to be streamed, and the rest all go play their matches at the same time/asap, seeing as they're all there and have been roll called, this would keep things moving out of the early slower rounds.
This was the method for TDT IV and I think it worked out quite well. It was all done and dusted within 2 hours. The problem with TDT V was that I had to throw Hablaskakaf and Cran under the bus as I wasn't able to run it, consequently the tournament did not run as smoothly as it could have given its last minute nature.
Rather than you guys trying to add every newcomer, then having some missing when it starts and asking people if they know them etc, make it part of the rules that you add a certain account/s (Kay/habla/cran?) as friend before the event if not already and if you don't add them you won't be able to take part.
This is already in the rules, but I should probably alter it to further reiterate this fact. It is an important way of how we do things.
As a possible future suggestion.. If it had a $2 entry via paypal, then perhaps there could be a small prizepool % as well as some funds going to the organisers to keep it up and growing.
I think we're on the fence on this one, we don't want to alienate people by charging an entry fee for an online tournament given how volatile the platform can be but then on the other hand it can provide an incentive (however small) for players to participate and actually give it a go. I would like to hear other opinions on this, I'm sure cran would love a $1 salary though...

One option might be to create a dedicated Steam group that is administrable by key organisers of the bracket.
i.e. "Tournament on X date, join <group name> to enter."
That way when you lock down your registrations and are ready to generate brackets, you will have a shortlist of immediately accessible Steam handles that the tournament runner can use as a shortlist to invite into the stream game lobby. For those not playing in the stream lobby, they can pluck out the Steam handles from the group of those they are scheduled to play next and fire them an invite. Anyone not present/online in the group after the tournament starts could be considered bksama'd. Also keep in mind that Steam groups also have dedicated chat channels, which would be handy.
This might help get around the "Is <player> online? What is his Steam name?" I noticed cropping up when Mike and I were commentating. Even if players aren't on your personal buddy list, a dedicated Steam group for this kind of thing will help people find one another and kick off a bracket match quickly. There would be no excuses for not having them as a contact (unless they are using an alias - which I suggest you request players register as their tournament name) so you could then start getting aggressive with start times, which in my experience is the only way to get online tournaments to run smoothly.
Steam groups ALSO facilitate event creation AND allow you to invite players by Steam name to populate a short list. It also fires out reminder notices to players in advance of events that are beginning which I feel would be handy.
Something to consider.
We already utilize steam groups and steam chats to run our tournaments. It's one of the bigger reasons why the PC platform works a lot better than something like XBL. I will again clarify this in the OP just in case some people have missed it, but we do require them to jump into the relevant chat room before the tournament and check in, there is also a check-in feature on Challonge that we haven't used because it might make things a little too confusing but we may try it sometime.
The biggest problems so far, ignoring the fact that V was run with last minute instructions, has been people not signing up with an at least somewhat consistent steam name, changing aliases, not being online, and not being prompt in their responses to TOs or to other players who need to organise a match against them especially if they are in the losers bracket. We do try to minimize these problems by adding players and assigning steam 'nicknames' to ensure we know whos who but when it comes to matches that aren't streamed, its a lot harder for other players to find you and invite you to your assigned match against them. The tournament (usually) will only take as long as participates take to ready up and play.
Thanks for the suggestions and thanks to everyone who has participated thus far! I only started these tournaments to network and meet other players so I could learn the game both from my fellow newbies, the scary intermediates, and those godlike players cran always mentions and so far it has turned out a lot more successful than I would have guessed. PC is a great platform and myself, Habla, and Cran I'm sure are happy to help facilitate this growth.
Still haven't gotten anyone godlike to accept my FT100 challenges yet though. >_>