Just spent some time talking to people whose job it is to sell and discuss systems management. No, really, it's more interesting than it sounds because it's actually not about technology at all.
Once you dig under the corporate rhetoric, what you find is that the sticking point is not about whether having one management system to rule them all is a good idea. It's more about whether the organisation is ready for it.
Let's assume that all IT departments want to become a service to the business. Their competition is effectively cloud service providers, so they'd better assume that this is where they should be going. The alternative is to be outsourced.
Given that, they need to be able to present metrics to the business about how efficient they are and how much value they deliver. This is the kind of language business managers understand. To do that, say systems management people, you need an over-arching system that sucks data from everywhere and can present it in a variety of ways, depending on your role.
For example, techies get down and dirty reports about which network or server function is working -- or not -- while the CIO sees trends data that allow him or her to report how well IT is meeting its SLAs.
The issue though is partly about whether IT is ready to deliver what it does as service, as its competition allegedly does -- although I think there's a faint question mark there. It's also about whether the rest of the organisation sees IT as a service or a financial drag.
Either way, it depends on a conversation that IT and the business can have to discuss how they can work together, or one that shows how far apart they are in terms of their Weltanschauung.
Is systems management the answer to the problem? Is this even the right problem to be attacking? I'd be interested to hear your views.