An interesting comment (among many) from Bruce Schneider and Adam Shostacks‘ response on SecurityFocus to Bill Gates “Trustworthy Computing” initiative:
There is only one reason for the Bill Gates Security memo. It has to do with the current consent decree offered by the DOJ in the antiturst case against Microsoft. It forces Microsoft to provide APIs and format information to developers except where security would be compromised.
Claiming that they are now “security conscious” will allow Microsoft to maintain secrecy while claiming they are being responsible for increased security in their products.