This is a bold move by Apple. Typically a search warrant is needed by the police to access private data, intercept telephone calls and otherwise search private property. The new Apple operating system provides no way for the company to bypass the device owner's passcodes. The company can still access the data stored in the iCloud since the Cloud information is not stored on the mobile device.
There will certainly be challanges to the Apple policy, especially in the wake of the 2014 United States Supreme Court decision of Riley v. California where the Supreme Court ruled that search warrants are needed by law enforcement to access smart phone data.