Well,
in my opinion there are a couple of significant problems here...
1. The people here have absolutely no experience with MAC programming... I'd say some of them have never
seen a MAC with their own eyes (I remember having seen one in my life). And, we don't have any such piece of hardware. While MACs may be more common in US, they are quite rare here.
2. The previous item somehow implies that the market wouldn't be very big either - i.e. probably not worth the effort.
3. avast! for Linux doesn't have any fancy GUI; however, MAC users probably wouldn't be very satisfied with a command-line tool.
Making a nice GUI is quite a lot of work - at least on Windows platform.
4. Some (important) pieces of avast! are limited to x86 platform. While we talked about some ways to overcome this limitation some time ago, the work hasn't been even started yet.
Of course, I cannot say what crazy ideas will Vlk come with
, but I'm really not very optimistic about MAC support.