I have been using multiple monitors for as long as I can remember (13+ years). And one of the best features that I have seen for multiple monitors is TeamViewers ability to "pop-out" a monitor. It would be great to see such a feature in Remote Utilities, where I could have two RU windows up at the same time, each displaying the specific monitor. In my case, I have three monitors so I would have three RU Viewer windows open.
Create two identical remote connections (to the same PC, that is). Open them in Full Control or View mode, and you will have two tabs connected to the same PC and same entire desktop. Then switch to the first monitor on the first tab, and to the second monitor on the second tab. Each tab then will be connected to its own monitor on the same remote PC.
You can also detach the tabs from the mother window if that what you mean by "pop-outness". To do that, open the View Options -> Remote Screen -> and uncheck Tabbed View.