Presumably, Haiku would have something along the lines of iptables for use as a firewall. Would there be a graphical equivalent or front-end, perhaps something similar to Zone Alarm for Windows, in the works?
A firewall certainly seems to be a necessary OS feature anymore, although ideally it wouldn't need one. I have no idea what's planned, but I'd certainly like some level of protection built-in (preferably with a GUI). But making something like Zone Alarm (or the Windows XP firewall) seems like it'd be a lot of trouble since it focuses on application level filtering (kinda pointless without spyware, and usually easily defeated). I'd think something like Look 'n Stop (also for Windows) would be more appropiate/easier to make. It's essentially just a rule-based firewall that lets you make rules based on protocol/port, IP, MAC address (a very useful but often neglected feature), and notification when certain rules block (or alow) things. Here, here, and here are some screenshots. I'm guessing that's similar to iptables, but with a GUI (I don't use Linux enough to know for sure).