Bringing free antivirus to Mac is a good thing IMO, especially since Microsoft has been doing the same for years.

I'd like to see much more behavioral analysis like the leading AV companies do, rather than just fingerprinting but it's a good start.

One thing I don't like about Apple's approach to security is locking the user out, making the OS like a black box. For me the user should always retain the last word. Until now most of their work has been in this direction (and the direction of iOS) but I'm pleased to see they're looking more into mitigation rather than just prevention now.