T gauge does have a few problems, as with anything new it takes time to get more people interested in it. The HST is great, and with the new controller, the PWM, which gives realistic speeds is a big step forward. I know track wise that points are not great, but a new version is in the pipeline. As for further releases, i think ready to run models might be scarce, but there are people who design and print locos in 3d which are good, only problem being you have to paint them yourself. Another slight issue is that there is not a 6 wheel bogie although again this will hopefully appear at some point. For coaches, electra graphics have done prints for them and also for a 150 and 205 dmu. Again for freight, those with skills far better than mine have created various models, again just add paint.
Personally i hope t gauge just keeps growing, i'm not a rivet counter and as long as the loco looks good that's good enogh for me. In process of making a layout and in a 6ft by 3ft baseboard i have two lines which measure 6.3 metres, or 1.8 miles if scaled up.
Dave