Q: Blu-ray and SACD

Apple themselves still do not provide a solution to play Blu-Ray discs, they do still include DVD Player to play DVDs. There are some third-party programs however that will do this although they are not 100% official Blu-Ray solutions. See the following.

http://www.macblurayplayer.com/

http://www.dvdfab.cn/mac-blu-ray-player.htm

http://www.leawo.org/blu-ray-player-mac/

Note: Due to the fact these solutions are 'unofficial' they typically do not have the ability to fully display and use the animated Blu-Ray disc menu and instead will just play the main movie on the disc, secondly due to the fact that Apple have not bothered to add underlying capabilities to OS X these programs also are not able to play the highest quality audio tracks from Blu-Ray discs and instead will either play a lower quality track or downscale a higher quality track. (It will still be at least as good audio as a DVD disc.)

Also note that all of those solutions originate outside the US as their US legality is a bit sketchy at best.

Blu-ray licensing is still a bag of hurt.

In addition SACD is a Sony design.  Even most DVD players will not play SACD's.  I play them on my Sony DVD player and while they sound great this format never early caught on.  Not many SACD's even available anymore.

The Apple Superdrive cannot play Blu-Ray discs.  You need a Blu-Ray drive in addition to the Blu-ray software.

http://eshop.macsales.com/shop/optical-drives/superdrives/

http://www.mcetech.com

Hmm. I just played a blu-ray on my 5 year old macbook pro when the DVD player (stand alone, hooked to TV) would not.

Grant

I'm a bit leery in installing third party programs on my iMac that could invalidate the warranty

Software does not affect the warranty.