The note was taken but there is not much we can do about it right now.. Yeah we 'just' need to create some checksums and compare those.. But creating such things needs time and someone to work on it.
There are cheats for every game that is out there. No matter if they use punkbuster or what else. Having a check for data integrity might make it harder to cheat but not impossible. Also many anti-cheat programs are bad performance wise as they keep scanning the harddisc for cheats.
And for a bad example: I heared bad things about Q4 in that regard.. That sometimes you get kicked just for having a map installed that the server does not have. Not sure if thats true though.
Yeah its nice to have some way to dedect cheats. It makes people feel better but its hard to do it right. I still think the best way to deal with this issue is to have user accounts. But as with the thing above it needs someone to do it

.
For the time being the ladder and posting screenshots and demos is the best way to know there is no cheating.
Some random rant thats close to the issue..
I got acussed of cheating again the other day. Was very late at night as i could not sleep. Ai was with me.. I really would like to know why only i got acussed.. Ai was at least as good as i. The funny (or sad) thing is that this f*cking b*stard left with the comment "time to delete this shit".. Guess he should get some common sense first.. why in the world would one delete a game because someone else was (in his mind) cheating? I'm really beginning to hate those whinners that can't stand getting their ass whipped after installing a game.. Some others play this game for a year. Of course he will get owned!