Yes, I think you'll be bored for that many days with 2 girls as young as yours. I think there would be enough to do for 2-3 days, but that may even be stretching it a bit. I've been twice in the last few months - once with my boys ages 9 & 12 and another trip with just another adult friend, and we had a great time. But my friend left her daughters of ages 2, 7, & 8 at home and definitely said there just wasn't enough that she'd be comfortable taking them to. That's why we took a Moms only trip and she's waiting several years before she'll take her girls.
I really enjoyed the parks, but don't feel that there's enough for the younger children. Sure, the children's areas they have are really great, but we're talking spending a few hours there - not 7 days! And the more adult themes of so many of the atrractions/rides/shows just may not be appropriate. My friend said there's no way she would have taken her girls to things like Terminator, Hollywood Horror Make-up Show, Jaws ride, etc.
If I were you, I'd save Universal for about 6 years from now and stick with Disney!