I know awhile back (18 months?) Tascam had a press release that they were no longer making transports as when the current inventory was gone, that was it.
The problem is the company that made the transports for the units stopped. At the time when Tascam had that announcement, they estimated they had about 3-5 years worth of inventory, that included repair parts if I remember correctly.
Even DAT tape has been harder to get. Real DAT tape (not DDS) has been limited to a couple vendors now, and my guess is that some point this will only leave Maxell or Sony. DDS isn't is much better shape really. However, all things considered, DAT still has some life, but I'm in the limited life category. That is, it isn't on life support yet, but it certainly has seen better days.
Wayne