You need the staff and good software...
Most IT staff are just barely able to handle supporting the Microsoft stack. Any additional complexity and they just tell the users "You will have to just deal with it because that is the way it is" and they walk away. I have seen this.
VMware VDI with Nvidia video cards are VERY good, you need Gig networking and a peppy thin client, not the junk $99 ones. I am talking about dual screen video and CAD. It can be done and that pool is separate from the general purpose users.
You have to give users access to multiple pools with different view servers so if one view cluster is down there are alternatives, i.e. another non persistent pool. Yes you need multiple DNS servers, if you have 1 you have no right complaining. DHCP is the same thing.
You also need documentation on software used on site as well as how to install it. yes some vendors need a kick in the nuts, i.e. the ones that still break rules that require administrator to get the thin to run or things that fail running on terminal server. We should be past junk win95 software that fails to run on terminal server.
Your mileage may vary if you use the substandard VDI vendors like Citrix or Microsoft. LOL