He's been living in France for 30 years, surely that is horrifying punishment enough! j/k.
Now seriously:
Roman Polanski is a good director, and yeah, it's terrible that his wife was murdered.
However, no amount of personal hardship can justify the drugging and raping of a 13 year old girl.
And much as I hate to prove Godwin's law right once again, if crimes committed 30 years ago are to old to be punished, as some people claim, how come we still hunt down Nazi war criminals who committed their crimes far earlier?
The fact that the victim wants to drop the case is irrelevant, since it's not a personal lawsuit.