Glad it was at sale price, I went over to The Mac Game Store and bought the Mac version there, buying both at sale price still worked out I got it under normal selling price.
True, it's just a shame it hasn't made its way to Steam.
It's the same for the id Software games, DOOM 3, Quake 4 and others. There are mac versions, but not on steam. Pity having to buy things twice, sometimes 3 times. 😛
The only thing you can do is contact Steam and see if you get lucky.
There's a chance it may get SteamPlay support in the future, Feral seems to still be slowly adding it to their older games. Empire and Napoleon: Total War just got it.
It's funny because Square Enix seems to have the exact opposite frame of mind. Hitman, Tomb Raider, and Deus Ex: Human Revolution all got ported. RAGE was done eventually. Hopefully Aspyr (more likely considering they were the ones who did RAGE) or Feral can convince Zenimax to cough up the rights for Wolfenstein, as it looks like a lot of fun.