The best thing for me would be a publish option for more systems like MAC or consoles!
Please keep in mind that you have to support this platform as well, which means that you need hardware to test your game on and you need to know the platform well enough to give support to your users.
This is coming from someone who is currently working on a project that runs on all major desktop and mobile platforms, and I wouldn't dare to support Linux and Android if I wouldn't work with someone who has experience on these two platforms.
And while an engine can abstract you a lot away from the underlying hardware, you still have to keep certain things in mind (okay, Mac OS X nowadays is x86-64, just like Windows, but on consoles you are suddenly faced with PPC CPUs and if you want mobile you suddenly have to deal with weakly ordered ARM CPUs. Changing platforms is no kindergarten, it's the exact opposite).