We already have single payer in the US - it's called the VA. Gov't owned and run hospitals and staff. Seems there might be a problem with corruption there, or so I've heard. Medicare, Medicaid and the VA couldn't exist without the support of those who are privately insured.
IPAB is a 'death panel' by any definition. When and if activated it will indeed decide who deserves treatment and who does not. Already a provision of Obamacare will be forcing some doctors to drop, or 'creatively' treat, certain patients with diabetes. It's one thing for a government panel to refuse to pay for a procedure, another entirely to forbid the procedure regardless of ability to pay - a by product of rationing. If the government says no in a single payer scenario, where ya gonna run to?