I just tried it and it works! You won't have to go back and forth between newsgroups to see if there are new articles in the group you are currently reading. Instead they are simply added to the view. I just wait for a bug to be fixed in R3 before adding it 'officially', so I do not need to use a workaround.
If you actually work with other than the standard system fonts, you will probably see some ugly things, like button labels that are to big for the button, etc. This will be fixed.
You will see some more flags for postings. They will allow you to write an article without sending it at the next connect. It will also be possible to mark interesting articles for later reading.
If I have enough time, there is going to be a second mode to read the articles. That mode would use more than just one window.
I wait for your suggestions.