"Is TDM going the way of dial-up?"

Unfortunately what you are seeing is indeed where the world is going,
and it is extremely painful to watch. My personal preference is the
direct opposite of that: Ethernet for non-LAN use is my very antithesis,
I hate it to the core of my being. V.35/HDLC forever for me! I will
continue using HDLC over traditional synchronous serial WAN media for as
long as I am alive.

MS

P.S. This message is being sent from a VAX running a variant of 4.3BSD
(Quasijarus). Almost the entire ARPA Internet software stack that's
running on my VAXen is mostly unchanged from how it was in 1988.