If the receiver has mch analog inputs (6 for 5.1, or 8 for 7.1), then you will want a player that can internally decode and send via these multiple analog cables.
If your receiver lacks those, then you will use optical/coax but without access to the lossless formats. Otherwise, you will still get surround sound just like before, as DD or DTS, etc. Oh, on that note, I like Panasonic. I think some players, like the Sony 350, are unable to recode mch PCM, as they call it, to DD/DTS. However, the titles that only have mch PCM without an accompanying legacy track are extremely rare, and for the ones I've read about, I could hardly care less about those titles anyways.
Hope this helps.