Having recently seen the flipside to this story, a tech startup with badly designed fraud mitigation building up huge losses very quickly (not one of ours, I hasten to add) it's no surprise that the payment providers are taking efforts to protect themselves from potential losses. Not giving you the money until the customer has had time to refute their purchase is the only way to safely do it, I guess.
Howies are launching www.teepay.com. Upload your design and market it as you see fit. If orders reach 50 Howies will print it out and ship it on your behalf, paying a royalty to you. Nice idea, if in an already cluttered space. The overall quality of their product may well enable them to win out, but their shirts are expensive too.