B&O "deselected" SACD, and chose to not include it as an option in their audio players. The format has had a hard time catching on (came out at the same time as DVD-Audio and while most people were turning to low resolution mp3 as "more than enough" for their needs.)
I doubt that B&O will go to a disc-based SACD format now given that more and more people are placing their music on harddisks -- but there are quite a few releases of SACD still, and it's becoming a connoisseur's format for music. In a few years we'll be downloading high-resolution multi-channel files of music as a matter of course, and these will deliver what SACD does now, and some of them may even be mastered as SACD, or in some of the other high-resolution formats.
At Musicgiants.com you can download 5.1 channel high-resolution music files today (from large portions of the Naxos catalogue). To use Musicgiants you need to have a PC running. There are also numerous other suppliers of high-resolution music downloads (such as Linn Records).
Is it different? That depends upon the acuity of your hearing and your musical taste. You will find many claiming it's no different from CD-quality playback, while others are adamant it is much, much better. I think that perception of difference comes down to the kind of music you are listening to - the format's caught on among lovers of Jazz and Classical, and I think it is best suited for acoustic music of that kind.
I like multi-channel versions and really feel the format contributes to the "in the auditorium" feel -- on good recordings you may also note a sharper attack and detail in the bottom of the sound frequency spectrum as well as better resolved high notes. In my listening room, I feel the music opens up much better at higher resolutions than CD. I have a few of the Linn recordings in 24-bit/88.2kHz and 24-bit/96kHz and the music simply feels smoother, richer.
I'd recommend giving the format a listen at a hi-fi dealer with a good listening room. Bring along music you know well, preferably in hybrid format (CDs with both Redbook (16-bit/44.1kHz) and SACD layers). Many players will let you switch between the two, and you can make up your mind.