No worries.  Things are not always obvious.

• The modules packaged with DotNetNuke are primarily community supported Forge extensions which we hold copyright to.  So we are able to distribute them freely and enable folks to start building useful websites quickly.  However, because of their community supported nature... it's unlikely that they will always be "best of breed".  Good? Yes.  Solid? Yes.  Most feature rich and enterprise ready?  Probably not.  This is the rightful place of 3rd party extension developers who form the basis of much of our ecosystem to build modules and business applications in their field of expertise.  We, like most other DotNetNuke sites, utilize a combination of packaged, 3rd party and custom modules to accomplish our needs.
• The Forum module is temporarily out of synch with what is available in the Forge, but not a lot and not for long.  Actually, there is a public beta of the next release of Forums available which contains more features than the one you are currently reading *grin*.  As soon as that version is ready to become a release candiate, we'll be dogfooding it here ourselves prior to release.
• The blog module on www.dotnetnuke.com is the same one in source control on the Forge.  We fixed a minor problem that we needed addressed (as any developer might do for their own site) and before long we'll be packaging up and releasing a new version of that too. 

No conspiracy theories, no sarcasm necessary *grin*.

Hope the information is helpful!

Scott Willhite, Co-Founder DNN