epicware just released a MacOS X binary of SDL. You can download it here from sourceforge or from their site at http://www.epicware.com/FunAndGames.html
A new release with source, Linux and Windows binaries. I will try to build a BeOS release sometime soon as well.
The main news in this version is support for the "standard" Loki keybindings for grabbing/releasing the mouse pointer (Ctrl-g) and for pausing / iconifying the game (Ctrl-z).
I compiled a Windows version of SDLRoids today using a cross compiler under Linux. It's available in the download area.
SDLRoids now compiles and runs fine on BeOS. There will be binary versions available here tomorrow probably.