You know it's good news when Luxury Rentals Manhattan breaks out the popchampagne.jpg imagery, and so it is in this case. Of course, rising vacancy rates are not the sort of thing that landlords pop corks over -- the tighter the market for NYC apartment rentals is, the more they're able to get for said NYC apartment rentals. But with October rental stats showing an (expected, seasonal) rise in the New York apartment vacancy rate, things in the Manhattan real estate market seem to have turned in favor of renters, after months of running the other way. Again, this sort of thing pretty much always happens in autumn, which is why it's the most wonderful time of the year for Manhattan apartment hunters. But that doesn't mean renters shouldn't be celebrating this particular bit of seasonal good luck. While CitiHabitats' report on the October rental market indicated that rents fell one percent from September's averages, the real news here is the rising vacancy rate -- and how it could wind up making concessions on NYC apartments a lot less rare. Thus the popping corks. Read on for the nitty gritty.