I have been bitten by a handfull of problems that could have been avoided if I had switched to another profile earlier. A lot of bugzilla reports seem to be caused by outdated profiles. It would help a lot if you could add a section (chapter) to the handbook about what profiles are; how a simple user is informed that new profiles are available and/or his current profile has been obsoleted and what steps a user should take to upgrade his old profile to a newer one.
We already have documentation regarding profiles. There is http://wren.gentoo.org/proj/en/releng/release/2004.0/releng/profile-update.xml and http://wren.gentoo.org/doc/en/gentoo-upgrading.xml. A user who starts with Gentoo doesn't need to know about profiles (yet) since the installation automatically takes on the correct profile; users who already have Gentoo installed should be notified by Portage when a change is needed. I believe the current documentation suits this purpose well.
Later on (within 3 months) a user will encounter a portage gently reminding him (once?) that a new profile is available... How should the relative Gentoo newbee act then? If you don't want to tell the full story in the handbook, fine. At least provide a pointer or URL to the information.
When the current profile is outdated, Portage will even halt until you use the new one. It will also tell you how to update. Also, when a new profile is introduced, information on upgrading to the new profile is sent out through the regular channels. Also, I believe that the document entitled "Gentoo Upgrading Guide" covers everything; the document (referenced in my first comment) is available from our website and linked from the correct places.
if a profile needs to be updated, portage will tell him exactly how to upgrade it there's no point in adding a section which simply duplicates the info that portage gives you
