Will's article refers to SiteEdit only (if I'm not mistaken). Your question is about a generic mechanism on 'including DCPs from a RTF field'.
Allowing other DCPs to be referred to from RTF is, in my view, not very kosher. I would even go as to say it is bad practice. I would avoid mixing content with layout (in the context of DCPs). I think that's something that should be done in a template or via metadata.
I think (D)CPs should be placed on a Page or queried for using some kind of metadata. I would probably prefer to have some taxonomies to tag a DCP against, then in another Component (let's call it a Control Component) you would specify some kind of criteria cocktail regarding which DCPs you want to query and display on the Page. The template will then generate some code (e.g. a custom tag) that would be executed on the Content Delivery side.
Alternatively to your request, maybe a list of links would make more sense for the authors.
Finally, to go back to your requirement, if you choose to go ahead with DCPs in RTF, then I guess it's just a matter of finding a naming convention on how to 'point' to the DCPs from RTF. One possibility would be to use a specially crafted Component Link (maybe with some specific target attribute) that a C# TBB would understand to parse out and replace with a <tridion:ComponentPresentation.../> call. I would use Component Links in an RTF because these links are maintained for integrity, consistency, porting, etc...