I know this is an old thread but I am new and wanted to add my two cents.
Anyway, I am not sure if we are into hobbyist territory. Me still using 35mm film SLRs from the 60s and 70s is hobbyist territory. This may come across kind of rambling and unfocused but I will try and make this as coherent as possible.
For me the Power Mac G5 I just acquired is a beast of a machine and is more then useful for my purposes and will be for sometime. Apple's lack of support really is a non issue for me. Furthermore with the cost of Apple hardware PPC is the best option. Where I live even on the second hand market intel hardware commands ridiculously high prices (very near full retail) and Apple is leaving early Intels in the dust anyway so I would be using a computer with no real support either way. And with a dual boot with OSX and Linux or BSD which I have experience with I will be set for sometime yet to come.
But even if we do enter the Hobbyist territory is it really that bad? If we want to keep our good machines running for years to come perhaps we don't have it so bad. Look at Amiga and the MorphOS group. Their company did not just stop support but went down in flames in the mid 90s and a dedicated group of users have kept their platform alive on "old" Apple ppc G4 hardware if you please. I think since computers went mainstream users have been giving more and more control over to the companies that make the hardware and software and feel trapped into the brilliant marketing ploy of planned obsolescence. As a side note I seem to remember part of Apple's deal with Intel being to kill support for PPC as a condition of the agreement since Intel is a direct competitor of IBM and Intel was able to make PPC support a conflict of interest issue. Not sure how accurate that is. I guess where I am going with this is the computers will continue to be useful for as long as they keep working and still fill a need in our lives and we need to remember we have a lot more say in how useful our computers are then Apple's Marketing department.
Personally I was disappointed when Apple made the switch to intel. Windows support was a non issue since I like many Mac users chose the Mac specifically because we did not want to use Windows on the software front. Plus with PowerPC the Mac truly was different and the switch was like Ferrari announcing the are now getting their engines from Ford consumer division. The Mac became just one more PC OEM. I can't see Apple making claims like they did with the PM G5 that I am typing this on about it being the fastest desktop in the world. How can they when the use the exact same hardware as everyone else? But I think apple has also gone from being a high end computer company to an electronic media appliance company. The ipad is not a computer it is an appliance at best and at worst a tech toy. And with the insane new high speed planned obsolescence I don't feel like this is the same Company that I have been happy with since my very first Apple 2 GS. I guess I took Think Different literally. lol
Rant over.