I wonder if this is just defensive. Given Nigeria's reputation for Internet scams and bit.ly's problems with Libya, would Microsoft really want to build a URL shortener around this TLD?
I tried hunting through the government website, and it lists a large number of registrars, but none of them seem to offer an easy way to sign up for one. Keep in mind the following things though:
I saw another Nigerian company for which an "exception" had been made. Overall, I think it's risky business right now, especially if you manage to snag a desirable .ng domain. I don't mean this as offensive, but it's not unimaginable in Nigeria that a few greased palms could lead to an "exception" being made for re-assigning your DNS record if you don't have local interests there to back you up.
Hi, I represent Websoft [www.websoft.com.ng], the Registrar for Microsoft's bi.ng. The Buy-Now process of 2nd level .ng domains is on & its not over-the-counter, here is it official link by the registry published in 2010