The only reason you didn´t hear something about iBook G4 users complaining, is that we are tough cookies;-)
The truth is, iBook G4s also get too hot, so the only solution may be to really place a pillow (or one, two big magazines) between your notebook and your lap.
Please consider that Microsofts infusion of 150 Mio. USD in 1997 and its committment to continue to develop Microsoft Office for Mac was a major supporting factor in Apples fight to survive at that time. Part of Bill's equation was obviously to keep a second plattform alive to counter claims, Microsoft was aiming for a monopoly.
Things have changed since then (Big Success of Linux and OS X) but still the non-availability of MS Office for Mac would be a show-stopper for anybody considering buying a Mac for home, while working with a PC in the Office.
I'm not a fan of Microsoft either, but I believe it would not be a smart move from Apple to piss Microsoft off with their own Version of Office.
Cheers
cubologic
Burns: The price to pay for G4 Power on your lap
Death to Microsoft