*If* the son has reason to use, already knows how to use, and has a licensed (expensive!) copy of Adobe Creative Suite, he should definitely be running Windows or OSX. You just can't YET replace that software under linux, especially Indesign.Or perhaps more to the point, why are you letting your children dictate what software is run in your household?
My education copy of CS2 cost me about $350 (the non-education version was about $900). I'm going to run an XP machine for years while I make the most out of that purchase. I'm not about to exchange CS2 for a clunky Photoshop7 under CrossoverOffice.
That said, I think XP will be my last MS product. Vista is out. Explorer, Outlook, Instant messenger, word and powerpoint are out (thank goodness). Cracks and anti-virus software are out.
OpenOffice is in (and is very good), pybliographer replaces Endnote, Gimp and Pixel do most of what I need for imaging (but I am still so much faster/familiar on photoshop). I'm learning to use Scribus as a future replacement for Indesign and it's pretty good, too. Gedit and terminal are in, and I like them all.
About the son not wanting to use linux: you can lead a horse to water...