Phew! I read your post as the British shop not selling pj's anymore, and you hoping America would follow! I like my pj's (for SLEEPING in!)
But yeh I think the furthest you should go in them is the letterbox, except in emergencies...
Ok, honestly.... for my 16th birthday I wore my friend's pj's into the city with a flourescant yellow work vest ontop.... I didn't go into any shops though! Just on trains and the park in Sydney city.