HTC/Valve claim to be working on SteamOS/Linux support, but it won't be ready at launch. I don't think Valve has given up on SteamOS yet, so there is reason to hold out hope. I had to install Windows for the first time in almost a decade for the Vive :(
I think they do care about it. The guy in that support thread said they're working on it just earlier this month. I think that's at least a step up from "maybe someday."
https://steamcommunity.com/groups/steamuniverse/discussions/...
[Anyone still on winxp is a dangerous maniac, and I sincerely hope that's not what the OP meant.]