thanks for contribution. I would separate that into two requests:
1) drag & drop functionality for groups management. That's something handy and nice to have for our users. But for others it's about filtering queries or dynamic queries if there are so many nodes where drag & drop is not effective. Anyway I suggest to create request here in feature request area, and let people vote: http://thwack.solarwinds.com/community/network-management_tht/orion-network-performance-monitor/orion-network-performance-monitor-feature-requests
2) simulations. Basically you would like to see what devices could be impacted if adjacent router, switch would be removed. correct? Is there a reason when maps don't work - you can visually see what could be impacted in a tree view? Please feel free to put more details to describe your problem.
I'll submit a feature request shortly.
As for item 2, what I'd like to use dependencies for, is to see/simulate how a change to one system can have a flow-on impact to other systems that depend on that single system. From a purely networking point of view, if I have a bunch of routers in a meshed network, and a change is applied (remember, any change to a system can have an unforeseen impact, therefore the potential to bring it down), Solarwinds will change the status of systems behind a device that is down as unreachable. By physically turning off a box, I can see what the impact is. But I don't really want to do that in a production network. Hence I'd like to simulate it. Ask Solarwinds, show me what will happen if this system goes down.
Then, I can expand that onto finer systems. If I make changes to IIS, that will bring down my websites, I could then want a list of websites affected with contacts so that I can inform the right people.
This sort of datamining using Solarwinds would be awesome.
For the moment, I'll just dream. :-D