Don't let the beard fool you. This is Neil Finn's son, Liam.
The eyes are a dead give away, as are many of the mannerisms. I'm not sure the voice is very similar but there's definitely a common musicality.
Having watched this video and listened to this song quite a few times tonight (via Dooce), I am happy to discover that very special Finn musical gene has been handed down. But it does make me feel awfully old. I still remember Neil singing Our Day, a song about his unborn son, way back in 1983!
Here's a live version of the same song as performed on the Letterman show. The drumming at the end is pretty awesome, but the voice of his back-up singer (who I believe is Jimmy Barnes's daughter!) is magnificent.
I've definitely gotta get the album!