Just an FYI, batteries are starting to become discontinued for the powerbooks. If you have any desire to get a second battery, ebay will soon be your only place to go.
I had a Newertech fail after 18 months so they are not for certain either, but after reading the
"Just how far can we go?" thread, even user replaceable parts are starting to dry up.
I love my PowerPC Macs, but I have to face reality a lot of times. Scarcity of parts is going to be a fact of life from here on out. It's unavoidable. More PowerPC Macs will begin to fail and there just won't be any parts to fix them.
As useful as PowerPC Macs still are to me (and they really are), there hasn't been a PowerPC anything (desktop or laptop) since 2006. So for PowerPC Macs, the best we have are 8 years old and that is an eternity in the computer world! And for me, that age is even larger, as mine are from 2001 and still work nicely.
As time wears on, more will fail and there won't be immediate resources to fix it. It's inevitable. Those that have finally went to Mac Heaven will be sold as a system "for parts" so we can cannibalize what is working and do something with what doesn't.
With PPC laptops, and I hate to say this, it's either nostalgia or a need to keep it going as long as possible driving it. As for me, my next laptop will be the mid-2012 MacBook Pros (the last ones that have user-upgradeable parts) or a Windows laptop of my choosing. I can't imagine myself getting a PPC laptop anymore, but that's just me. I have enough software that would be a PITA to run on it now. Your mileage will vary.
Now I'm really hoping to get another few good years out of my old PowerPC's, though. It's going to involve a few decisions and one final push by going back to OS 9 (and the tons of abandonware it offers) full time when 10.5 is no longer a viable specimen. That time is coming soon for my G4 Digital Audio, as 10.5 offers nothing anymore that 9.2.2 cannot. My G5 tower, though, will remain on 10.5 until the bitter end, as it's still a monster to me.