The recent update of the RAD Studio 2009 Help (see Dee Elling blog post and the readme file by Kris Houser) provides full HTML-based navigation of Delphi help files. That's a significant step forward for the docs team at CodeGear.
If you jump to the docs home page for RAD Studio, at http://docs.embarcadero.com/products/rad_studio/ you can pick the various documents in various formats, but what is new (or at least seems to work much better) is the ability to refer to individual classes and individual methods of those classes with a specific URL, so that you can bookmark online help pages and post links to any of them. For example, the list of TObject's methods (show below) is available at the following page within the delphivclwin32 guide: !!MEMBERTYPE_Methods_System__TObject.html.
If you select one of the methods, say ClassParent, the URL of the page becomes: System__TObject__ClassParent.html which is composed by the unit name, the class name, and the method name.
Now the full URL is very long (http://docs.embarcadero.com/products/rad_studio/delphiAndcpp2009/HelpUpdate2/EN/html/delphivclwin32/System__TObject__ClassParent.html), so we'll all have to use URL shortening services or come up with a specific proxi redirecting to the delphi docs. Also, some of the summary pages are not the best choice (the content page shows a list of units, while I could not find a list of classes, much more useful for me). Summary pages seem also very slow, while individual pages are somewhat faster.
There is still work to do (like letting people contribute to help pages), but this is a significative step in the right direction. Kudos to the docs team at CodeGear.