Download Events and In Game events are two separate things. We can still have Darkrai confirmed later on in the B2W2 games as an event like Cresselia. The Strange house could be for Darkrai like some of us think.
I don't think there is any place better than that one unless the house is full of Ghost Pokemon like the Mansion in D/P/Pt. There is defiantly an event that happens there.
Maybe a buy-able house like in Platinum or a new Trick house like in R/S/E?