I do not believe that Bitcoin is yet ready for government level use. It is not yet ready for a large business.

Companies/governments need to have staff that spends money. Right now those large businesses have processes in place for how to track all of the money going through the system and how to keep people accountable for spending (two signatures on checks, receipts, ledgers, etc.).

Imagine someone in accounting having a Bitcoin wallet on their desktop. Not only would the accountant be able to copy that wallet and take it home for later use (or skipping the country), but so would IT and possibly anyone else on the corporate network.

I am not saying that Bitcoin is not able to be used in such an environment. Just that the processes and software/services have not been properly vetted yet to do so.