My initial thought was that it might be useful for Sarah's feral cat trapping antics, but alas the FAQ says it's not recommended for outdoor use, so I doubt it would perform well in low light.
Having just watched the promotional videos, I see where this would come in very handy in the smart home I'd like to build one day... It'd be so cool if when we were away from home and the home detected an intrusion, notified me, and then dispatched a Rovio to show me what was going on. Then I could call the police if necessary.
The one immediate downside I can see is that it only seems to support WEP. How 2001.