http://abcnews.go.com/US/aruba-suspect-gary-giordano-walk-free-today/story?id=14463749
Yes it is a copy of the actual signature on Robyn Gardner's Change of Beneficiary Form. It is in the video at above link.
If the signing was witnessed, there is no proof of it on the form. Some of the Change of Beneficiary Forms online have a place for a witness to sign. This one does not.
Is that date May 11th, 2011?