Has biwire speaker cabling become "old" ?

I'm with Z on that one. It usually is keeping the skin effect off the lower end cables and many other things that cables deal with. I was only able to afford a pair of AQ Castle Rock bi wired, but I've heard the same speakers I own with TWO separate runs of the same cable in the same system and HOLY COW is there a difference. It wasn't slight to me either. Anytime you can keep signals separate it's usually a good things. The signals are different on each run and it's night to keep them away from each other if you can. Higher resolution systems will shows the differences most of the time.

Funny thing, my Dunlavy speakers have bi-wire terminals. If he didn't believe in them why did he put them on his speakers?

Funny thing, my Dunlavy speakers have bi-wire terminals. If he didn't believe in them why did he put them on his speakers?
Rja

Because some marketing types told him audiophiles demand it.

Anytime you can keep signals separate it's usually a good things. The signals are different on each run and it's night to keep them away from each other if you can. Higher resolution systems will shows the differences most of the time.
Ctsooner

Not sure where you got this information, but if you are biwiring using only one amp, the signal is identical on both cables.

03-20-15: Rja
Funny thing, my Dunlavy speakers have bi-wire terminals. If he didn't believe in them why did he put them on his speakers?

Speaker designers do this for many reasons. Bi-amping is a higher priority reason that speaker manufacturers use multiple binding posts than bi-wiring though. Another reason is marketing, and meeting consumer demand.
Believe it or not, some people won't buy speakers if they can't bi-amp/bi-wire.