Unicode normalization is available in the unicode/norm package from the go.text project.
import "code.google.com/p/go.text/unicode/norm"
nfd := norm.NFD.String(str)
nfc := norm.NFC.String(str)
nfkd := norm.NFKD.String(str)
nfkc := norm.NFKC.String(str)