This frosting is AWESOME. It is rich and creamy and very tasty. I might suggest that people had problems with it being runny etc. because they did not beat it long enough in the mixer.
Mine was creamy and fluffy and I beat it on high for at least 3 mins. (I also used whipping/heavy cream instead of milk.) Try this! Excellent on dark chocolate cake.
I used this to frost Old Fashioned Kentucky Nut Cake from this site. The cake wasn't that great, but the frosting was. This frosting is delicious. It is so easy to make. Make sure the butter is soft. I micowaved mine for less than 10 seconds and it was perfect.