Dude,
I am a strong supporter of keeping PowerPC alive.. and also believe that both platforms of Intel and PPC serve specific purposes.. First off, what windows do you want to run on the ibook G4? Your best bet is going to be windows 2000.. You could get away with running windows xp, but you would have to turn off all the eye candy and fancy-shmancy stuff in there for it to run somewhat ok..
Also, max out your memory on the ibook G4. You should have no problems.. if you need virtual pc, I can help you with that.. I have a 2010 6-core mac pro and my PB G4 is used 70 percent of the time because what I do on my PB is everyday stuff as I also use my Mac Pro the same..
The iBook G4 is still a nice little laptop for basics and small windows work, but depending on what you wish to run on windows it might be better to get a small windows laptop or an intel mac.. BUT IN NO WAY AM I ADVOCATING YOU TO GET RID OF OR JUNK THE G4 iBook.. There is nothing wrong with running two platforms... Here is what I have:
2010 Mac Pro 6-core - originally was 2009 but replaced logic board and processor board - 300 dollars.. processor was only 800.00 for the 6-core which i purchased back in december 2010. My original processor was a 4-core 3.33 w3580.
PB G4 1.67 w/2GB DDR2 memory, SSD drive(PATA).. optimized to handle up to 720p youtube through mplayer os x extended using quicktime codecs and non-flash based codecs.
G4 Pismo - used for my OS 9 work - sheepshaver stinks
Gateway P-6860fx gaming laptop which has Windows 7 on it and 8GB of memory..
So, you see... Intel and PowerPC can co-exist. Don't let anyone else tell you otherwise.