Azatty,
I, too, would love to be able to upgrade to a Beosystem 3; however, the cost is prohibitive. Also, the BS3 still has some serious shortcomings that I predict should be rectified by B&O once B&O unveils its own BD player. For example, the BS3 still lacks HDMI 1.3, 24 fps, and the advanced audio codecs used by many blu-ray disks. I certainly don't want to invest in a BS3 and discover that an improved version becomes released shortly thereafter.
It's my understanding that the PS3 only offers an optical audio connection rather than a digital coax -- unless you have an optical to digital coax adapter. I use a Monster optical cable; however, I think that a cheaper optical cable would be just as adequate. This will provide for you the Dolby Digital and DTS audio. Also, as I mentioned in an earlier post, you can now take advantage of 2-channel SACD with the optical connection. Note that the PS3 settings do not allow the option to output in BOTH digital optical and analog RCA cables. You must choose one or the other. Prior to the firmware update that now enables SACD over the digital optical connection, the only way (lacking HDMI) to take advantage of SACD was with an analog RCA connection. However, now the digital optical cable takes care of all your needs.