] The Supreme Court today placed more limits on the power
] of judges to decide sentences for criminals, voting 5 to
] 4 to set aside a prison term in a Washington State
] kidnapping. The four dissenters predicted that the
] decision would wreak havoc on sentencing procedures in
] many states, and perhaps in the federal penal system as
] well.

This doesn't seem to directly speak to minimum-sentence laws but I'm
not really familiar enough with the case-law to say...

Justices Tighten Limits on Judges in Sentencing