Okay, just got done watching this and I thought I'd give my thoughts. I thought the first one was okay, and I really didn't think a second was necessary. I didn't see either of the films in the theater. I saw this at the video store and figured why not. In order to keep this spoiler free I will just say what I liked and disliked about it without giving anything away.
This film is shot much the same way as the first one, with lots of hand held shots. They also utilize multiple security cameras throughout the house. Eh. Most of this film takes place before the first film and they do a pretty good job of linking the two.
If you liked the first film you'll probably like this one too. More of the same, but I think I liked this one better. Its more creepy than scary, to be honest. It follows a family with a newborn baby this time which does increase the 'creep factor'. Should you watch it? Yeah. It's not a terribly long film and if you like this kind of stuff you'll enjoy it. I did.