For at least one of my clients, I will (almost) definately be using a VPS, as I would like to run mod_mono (ASP.NET Module for Apache from Ximian), rather than trying to translate it to PHP from ASP. I assume that this would be allowed?
We just moved over to the dedicated server plan and I I'm not sure if this is what you're inferring, but I don't think that you can run VPS on a dedicated server.
In addition, the control panels for accounts on a dedicated server are very simplistic (similar to those in WH 1.0) and the documentation is pretty sparse.