Ok, I have no clue how many people are in the queue at any given time, but I can check how many games are played. Note, though, that I probably miss a few games, because I can only retrieve matches where at least one of the players has a rank on the ladder. Comparisons to coh2charts that I did a while ago indicated that the difference (if existant) is insignificant.
Here are the number of games played in a given minute per mode over the last two weeks (time is UTC):
Edit:
Clarification: This shows how many games were running at a given time. Equal amount of games in a given minute doesn't mean that the number of games played in a day or so is the same! Many short games could give the same line as a few long ones.
And thus, the number of players:
The maximum for last week was 2014 players, Sunday 20:10 UTC.
The maximum number of games were 76 (1v1), 124 (2v2), 83 (3v3) and 122 (4v4), all at different points on Sunday.
Again this is only the number of games going on in the same minute, it excludes people waiting in the queue!