To be sure, once T hit the streets, new products came fast and furious. Buildings, people, trees, just about everything. Granted, there were a few "holes" that took some time to fill, such as automobiles. (Backstory here: Eishindo refused to sell "generic" vehicles; they wanted to make scale replicas of real cars. But the 1:1 car manufacturers wanted outrageous licensing fees, which placed a significant damper on Eishindo's plans.) Still, it was even more encouraging to see new train sets on the way, even as they were delayed for improvements—itself a promising sign.
But then little things started happening that hinted at a troubled future. The first noticeable sign was a significant drop-off in traffic at Talking T Gauge, to date the only successful discussion board dealing with T. At first I thought this was due to summer slump—a perfectly normal, hobby-wide annual cycle. But the slump never went away; indeed, it seems to be getting progressively worse.
This coincides with an unfortunate drop-off in new product announcements from Eishindo. In this business, no news is bad news. They had a lot of items on their drawing board, and we were seeing encouraging progress reports—even delay announcements were welcome. But now... crickets.
Recently I was exchanging emails with a T Gauge modeler who alerted me to the fact that a major retailer announced that spare parts would no longer be available from Eishindo. It may be nothing, but couple this with a "reorganization" announcement on Eishindo's website, and I can't escape the feeling that this portends potential problems.
So, has T Gauge run its course? Or about to? Is the fad winding down? I confess that I've not been motivated to do much at 1:450 lately. Is the thrill wearing off for others as well? I'd still like to build a substantial layout, but I'm finding it difficult to motivate myself.
There are so many limitations imposed by the scale that our modeling options are few—not to mention the long list of performance issues, some of which will likely never go away simply due to the physics involved. Even if I donned my "extreme scratchbuilder" hat and made everything myself, including mechanisms, there are things I simply couldn't do.
For instance, a freight train is pretty much out of the question; even if I modeled cab-style diesels to accommodate the mechanisms, I'd still have to power many of the freight cars in order to provide enough pulling power to move anything more than about three or four cars. (Bear in mind that the extreme light weight of a T scale locomotive reduces its tractive effort to the point that it can barely move itself, which is why the wheels are magnetic—and magnetic wheels add tremendous drag; this vicious cycle severely limits the number of free-rolling cars that can be pulled.) Based on my experience in the scale so far, a functional freight train would be a virtual impossibility—at least for me, as I lack the skills and equipment to produce an ultra-precise micro-mechanism, much less a dozen of them. There are precious few Arthur Sherwoods in the world!
So as a matter of practicality, our modeling options in T are pretty much limited to passenger trains, in particular urban mass transit—exactly what's available now. There aren't many serious (or even quasi-serious) modelers who would be happy being permanently restricted to these options.

Regardless of the future of T Gauge, Eishindo is to be commended. They made a valiant attempt to introduce a "real" scale, in the sense that their products are well and truly models—as much as they can be given the limitations—as opposed to merely making toys, such as Bandai's ZZ scale. My sincere hope is that T can somehow survive—but, to be perfectly honest, I have doubts.