Most organizations can benefit from both but the key to understand what problems you are solving with Virtualization, not just blindly implementing them. For example, if you have a fully burdened physical server, it may not be a good candidate for virtualization. For desktops, depending on applications, desktop virtualization may not be the answer. For example. if your primary problem is application compatibility and interaction, App-V may be the better solution.
One organization that can greatly benefit from desktop virtualization is hospitals with nursing stations. We have several thousand nursing stations and the nurses log on generically and then log into applications from there. They have no need to log into the station as themselves because many nurses share each station and they can’t lock each other out. So virtualization is ideal in their case. No local drive space is needed.