The Calgary Herald has a good interview with the CFL's head statistician, Steve Daniel. Well worth a read.
One interesting tidbit from the article:
"After 73 games this season, for example, CFL teams had used a total of 566 players, with an average age of 27.41."
Since there's nine teams, that's an average of 62.3 players per team. I would be curious to see the stats for each team this year. I remember that last year the Cats used a ridiculous number of players due to injury, although somewhat counter-intuitively Hamilton made it to the Grey Cup.
One stat I've been wondering about is pass knockdowns. Does the CFL track it? In some ways it isn't as good as a sack since no yards are lost, however with the recent trend of sacks being nullified by roughing the passer calls, a pass knockdown never really has this danger.