There are 2 problems right now.  This solves the second one.  I came up with this fix first, just explained it in irc .

1.  Server load.  This is not a problem that we can fix for now.  This is actually NOT the bigger of the two problems.

2.  Inability to join or start games.  The game is run P2P which means that everyone needs to connect to everyone else.  Due to the way the game is coded, if any one person fails to connect properly, EVERYONE who is not yet in a game lobby will timeout and be unable to join, it gets stuck in a loop.  THIS is the reason most games can't be started and this is a problem we can fix!

The solution is VERY simple.  The issue comes up when multiple people try to join at the same time and 1 crashes.  The solution?

IF YOU ARE HOSTING, ONLY HAVE ONE OPEN SLOT IN YOUR GAME AT A TIME

Open a new slot after someone joins.  After they join, open up another slot, etc, etc, till you have the number of players you want.  If you have 5 people who want to join and they all join at once and one of them is "bugged", none will get in.  If the third person to try to join is bugged, you'll at least get the first 2.  Once it says you are trying to connect to other players, it will never take you more than 2 minutes to join, usually less, 30 seconds or so-IF YOU ARE UNABLE TO JOIN IN THAT TIME the odds are fairly good someone who is "bugged" is also trying to join.  Look for another game.  You may get in after 2 or 3 minutes but only on rare occasion, the overwhelming majority of the time if its longer than 2 minutes, someone is "bugged", most of the time if its more than 30 seconds, someone is bugged.

If you are hosting, click on connection info on the bottom right, if anyone is trying to join for more than 2 or 3 minutes, someone is bugged.  Tell those in the game you'll have to remake and remake, or go with the players you have.

Keep in mind that the fewer players you are trying to get, the easier it will be to start a game, 2v2s are fairly easy, 3v3s are doable but usually hard, 4v4s are nearly impossible to get going.

The nightmare AI is actually pretty challenging since it gets enormous bonuses, do not be afraid to use some AIs.

Keep this thread bumped.  I will edit the original post if new information comes to light.

Edit with an update:  Multiple people can try to compete for the same spot, which makes this method fare less useful.  If any of them crash, they still all crash.  However, most people do not like to join empty games.  By only having 1 slot open, I was able to reliably lure people in 1 at a time, till we had enough for a 2v2.  Just made 3 2v2 games quickly this way, so it works.