So after reading a bunch of the internet, the team responsible for the NeatBeans UML plugin is working on it, but it isn't done yet. They have decided to start over because the old code is unsustainable, which is why it doesn't work with 7.x.
Nevertheless, as this post points out, people want UML Diagrams, so below is a link to my blog, which provides a way of getting UML Diagrams of your classes from NetBeans 7.x.
http://imagine.kicbak.com/blog/?p=58
You cannot generate code from diagrams with my solution, but you CAN generate UML Diagrams in your JavaDocs from your classes in your project. This is a Code -> Model solution only. Hope it helps.