At last, some hard stats on 3D Secure, the alleged biggest conversion killer of time....

The average abandonment rate increase caused by 3D Secure on an e-commerce website is 2.2%. That's 2.2% in addition to the 50% standard abandonment rate.
Shocking? No. Because there's a BIG mitigating stat: with 3D Secure, the approvals rate is 93% versus 87%. That's a net 3.7% improvement in gross sales.
Verified by Visa now has a 48% e-commerce acceptance in the UK and 88% of that volume was fully authenticated. Fraud rates are 3x better on websites with Verified by Visa (as opposed to without)and "card not present" fraud dropped by 19% in 2009.
With thanks to Jon Prideaux of Secure Trading for the insight.