Definitely,
I switched from Windows to Macs for about 5 years and have been extremely happy(although I do have to use windows everyday at work still). I think Macs basically make a perfect development platform, OS X is very solid and secure and runs well, a Flex, Apollo, Flash all run great, as does Flex Builder and Flash CS3 etc. And since you can run Windows and Linux with Parallels you have access to pretty much every OS you could want or need.
