Forgive me if I'm being dense, but isn't this concerning how rapes are investigated? I don't think burden of proof is being altered in any way, it is just an attempt to get more complaints taken seriously and followed up.
A buddy of mine's sister is a police officer, who works in whatever unit or department that tends to deal with these cases, and she is of the opinion that a certain significant percentage of allegations is false (I've not retained the precise number as I believe it's bullshit).
Thing is there is a lottery, depending on where you live will relate to precisely how seriously the police will take your complaint. My locality is certainly not the worst, but it's up there (hence why this particular officer's opinion is likely to be indicative of a regional bias).
This focus on how rapes are investigated, should help close these regional divides, help the police do a better job, and should be welcomed.