I stopped by the Chinese Consulate this morning to request a visa for my trip in January to Shanghai. The woman behind the window (she didn't look like a Godless Communist) was concerned that I was requesting a visa too early. She explained you have to enter China within three months of receiving it. We did the calendar math together and she relented.
It felt a little odd leaving my passport behind for "processing." But I have a reciept in Chinese -- so I guess I can rest easy that it'll be there when I go back next week.