Combine sugar, butter and eggnog to a full boil in a medium-size saucepan. Stirring constantly to avoid burning, cook until mixture reaches 238 degrees (soft ball stage). Remove from heat and with a hand mixer, beat in the white chocolate, nutmeg, marshmallow creme and vanilla extract. Beat until smooth and creamy . Pour into your 9x13 pan. Cool, then cut into squares. This fudge freezes very well until ready to serve.