If I was on the Mono team, I'd make it a priority to put together a simple one-step way to get your server up and running to the point where you could xcopy an existing ASP.NET project across and expect it to run.
I may have done Mono some injustice - it's actually not that hard. The toughest part is installing the latest Mono stable, and that's more of an issue with Ubuntu than with Mono. If you choose another distribution (SuSE and Arch come to mind), you could probably make your life a lot easier as they have more recent versions in their repos.
If you can stay away from the bleeding edge and don't have to install the latest version yesterday, the Badgerports repo solves the first part of the article for you, and you're left with configuring nginx and XSP's FastCGI server which is more-or-less equivalent to any other FastCGI setup with nginx.
I do think it could be easier than it is, but it seems to have more to do with the Ubuntu/Mono relationship than anything else.
It pretty much boils down to how much customizing you want and the particular components you select to implement your application. The more customization you'll require the more setup work you'll have to get it. That goes for any platform and any mix of tools you pick, not just mono. With that said, if you just want a basic setup, you can get one just as easily as any of the competing platforms.
