I've had the same problem with greenlandic somehow being excluded from the languagelist from Microsoft. But faroese is there, which is a bit odd since both Greenland and The Faroe Island are a part of the danish kingdom, and have a similar amount og people speaking the language... But...

I 'solved' the problem by changing the code in DotNetNuke.Localization.Localization.vb
The sub LoadCultureDropDownList has a select structure that 'translates' the languagecode to a text string.
In Greenland, the typical languages that need be supported on a website are greenlandic, danish and english.

Case CultureDropDownTypes.NativeName
                            Select Case item.Value
                                Case "nb-NO"
                                    item.Text = "Kalaallisut"
                                Case "da-DK"
                                    item.Text = "Dansk"
                                Case "en-US"
                                    item.Text = "English"
                                Case Else
                                    item.Text = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(info.NativeName)
                            End Select

It's not pretty, but is seems to work - even in the multilanguage modules that Delisoft and Apollo have made. Anyone have a better solution? This solution works with DNN 3.2.2