Stand in line GI Joe, the Japanese/Chinese/Korean and Europeans are way ahead of the americans when it comes to Myanmar. (tourisnm, business...)
Granted the US have a shiny Embassy there but you would be hardpressed to find an american in the street or anything (aside from Coca Cola and Sprite, there is barely anything american in Myanmar)
In terms of gvt relation, President Thein Sein has embarked on a program of opening the country which automatically means indeed that the US and all other Eu?westerns countries should be able at some point (assuming this movement of opening the country continues) to do business there relatively in line with what they do in other countries in the region (vietnam, cambodia...).
It's a very very long way to go and Myanmar is nowhere near where Vietnam, Cambodia or Thailand are in terms of development.
It's an awesome place though but that's another thread altogether,