While I'm a PC gamer, PS4 + ARR = Good news.
Furthermore, since PS4 is DX11 and all, I expect the client support to go that way:
Initial PC (+PS3) client: As they are now, with the PC client more optimized for visual candy.
Future PC client: Will convert to DX11, I've read that they will do that, but with a different client.
Future status: Current client for PS3, DX9 or whatever it is, + low end PC's , "HD" client for modern PC's + PS4.
Sounds like they'll need to support two clients, but they're actually getting 4 "markets" (low-end PC, higher-end PC, PS3, PS4). Win-win, I think.
I'm only basing the above on the fact that the clients are not 1:1 the same, so they could maintain 2 "branches" if they so wished.