Heh, just posted about this today. viewtopic.php?f=55&t=11616#p140397
Following the "white" Adagio theme, a white high quality Gaiwan would be great.
Also a white porcelain Japanese tea set including cups, water cooler, and a perpendicular handled Kyusu sans infuser basket ... instead a quality screen at the base of the spout. Oh, and authentic Japanese, not a Chinese knock off.
EDIT/add: These could be Adagio name brand items! which could be complimented with non Adagio name brand similar items for variety beyond the basic whites.
I am NOT a fan of the Tetsubin teapot/cup idea in your article, perhaps a few styles ... the more classics like hob nail, but Teavana does the Tetsubins to death with every motif under the sun, and they are really not overly functional.
Most members who discuss Teavana talk about the mistake people make in buying Tetsubins *raises hand* only to have them sit around as expensive paperweights. I don't think you want to resemble Teavana, yet that should not in itself preclude you from including items they also happen to sell, just don't repeat their tactics/model.