It has. But there is still the ol' quirks. I had problems with sounds on ubuntu on my ThinkPad. I had to install XFCE for it to play nice with 2 monitors (since the gpu in the old laptop is kind of sucky). But Macosx has even worse compability, so if you buy computer parts that are knows to play nice with linux you'll have a swell time :).
Also, when you start playing with tiling window managers you'll be glad you don't have a mac.
Also, when you start playing with tiling window managers you'll be glad you don't have a mac.