I'm not sure I understand what advantages incorporating offers to the Bitcoin Foundation, when (a) it facilitates legal targeting by the government and (b) does not further their stated purpose beyond what they could achieve as an informal working body. If Bitcoin becomes successful, that success will threaten governments and they will seek to suppress or control the currency and its associated organizations. If the Bitcoin Foundation is in this for the long term, then, like bitcoin itself, they should be focused on establishing their legitimacy outside of the governmental sphere.

You didnt really think 'the government' was going to leave you alone, did you?