basically I want to see all my work emails in my google account. We used to have forwarding to google - but google started to reject our mail recently claiming it's spam. So i'm thinking about making gmail to download emails from Exchange via POP3 - but I don't want to enter my AD login/password there (call it paranoid :)). Is it possible to specify separate password for POP3 access in Exchange 2010?
No sir - a given account has one password, regardless of protocol. You could solve this by forwarding all of your mail to another account with a different password, and POP-ing it into Google that way.