Various install/build tools such as easy_install, paster, buildout .. grokking {README,INSTALL}.txt and performing manual steps. Products should always have quality documented install procedures at point of issue. covers most of this, yet the conformance should already be in place at the time of Plone 3 stable. Back-porting of packages to that end should also be a reachable goal.

If Plone is to gain wider adoption these would be the stumbling blocks to that end for many organizations.