I've added a few additions to the "Add Dependency" dialog in NetBeans 6.7 daily builds (and the upcoming Milestone 3 of 6.7)
First, the dependency's Version field includes all properties defined in the project that end with .version, eg. ${spring.version} as suggested in the Maven Book, Chapter 8.3.

Second, I've created a new tab called "Open Projects" that lets the user pick from the list of currently opened projects and declare them as dependency of the current project.

Enjoy

This is awesome - the dialog the way it is a bit user unfriendly; usually when I pull it up I immediately decide to go and edit the pom file by hand instead - this makes it a lot more convenient - thanks!
I dislike this dialog UI design. See from my blog entry.
http://hantsy.blogspot.com/2009/03/maven-support-in-netbeans-67-m2-en.html
Another suggestion, use button "Add" and "Close" instead of current "Ok" and "Cancel". The difference is that I can add more than one dependency without close it and open again.
hantsy: Add/Close sounds ok, regarding your comments in the blog, I don't see how former "Find dependency" is better than current state.. you can use the Query tab to do exactly the same, you don't have to use the completion in the text fields.
I have explained it on my blog.
Firstly, I am sorry I am a none-English gay, maybe my explanation is not clear.
1. ***I think it is no use for most users, everybody need an effective way to add dependency , since it is no use, why not make it disappear in GUI***.
Not everybody can remember the first part of group id , artifact id of every maven artifacts. For example, if you want add "common logging" dependency to your project, it is a apache project , you maybe guess the group id is "org.apache.commons". But you are wrong , it is "commons". In this way , I wasted much time on guessing the group id and at last I had to give up , and turned to use the Maven repository browser to search it. Obviously this feature is no use for me. My suggestion is remove it from NetBeans 6.7, use the simple query-style view instead it. In this approach , it must search the keyword( the word user input in the query field) in group id , artifact id , package name and full class name of all artifacts in the whole maven repository.
2. Apply the KISS principle in NetBeans GUI design. Everybody like a united GUI in NetBeans.
In the "Navigate" menu, all "Go To" dialogs use this simple UI style.
My meaning is the "Query" feature is enough
hantsy: I still don't understand your rant about the dialog. There is a QUERY panel at the bottom of the dialog, that has the entry text field that lets you query the repositories and once you select an item there, it will use it and populate the top of the dialog. So the dialog lets you do all the things you write about. What's your problem?
Milos:As you described, if you select an item in the query result. I will populate the top fields. The infomation in the three field is duplicated with what you have seen in the result list when you selected it. So the top part of the dialog has no help to users.
If you want to enter information of an artifact directly in the top three field , You will encounter the problem I described in my blog entry. So at this point, this is also no help to users.
Just want to thank you for the maven stuff in netbeans. I use it all the time and I am really happy with it!!
(Although compiling should be faster, but this is a maven issue I guess)