I don't think pressuring Toady into releasing DF merch is a good idea. He has made his decision, and I'm sure he would change his mind if it ever seemed appropriate to him. We can't pretend to know his entire business model, and what he's doing now seems to be working just fine.
If you really want DF gear, go custom order some. Armok knows I would buy official DF gear in a heartbeat, but if you're really willing to spend money to help this game, then buy something from Zazzle (or whatever) and wear it proudly, and donate however much you feel appropriate to the Toad lord. No reason to muddle up the process.
Even if there was official gear, that would just mean Toady was paying the manufacturer's cut instead of you paying it yourself. At the end of the day, when all the dollars have settled, there is very little difference between Zazzle (or whatever) + donation and official gear bought through Zazzle (or whatever).
Does Zazzle's T-Shirts have that glossy stuff for the design, or just ink soaked into the cloth?
It's that glossy stuff printed over the thread. And it doesn't come with a menacing microcline spikes option.
I think Dwarf Merchandise would be a big success because it's safe to say Dwarf Fortress has the most game depth and has the most complex learning curve while still being fun.
That's why the GAME will be a bug success. That doesn't necessarily translate to successful merchandising.