I did own the very last PowerMac G5 model - the 2.5GHz Quad - and I sold it earlier this year because PowerPC support has been dropping. I bought my PowerMac in Dec 05... months after Apple announced the transition to Intel.
Why did I buy it when I knew they were going Intel? Simple... it made sense at the time because all the software I was using at the time was PowerPC native and going Intel that early would have been a mess for me.
Fast Forward to 2009 and it is a different story. The main app that I use, After Effects, is now INTEL only. Did I cry about it?... NO. My hardware was already over 3 years old and it was time to upgrade anyways. After Effects CS4 isn't the only Intel only app. Many apps are Intel only now.
I for one am glad they cleaned up OS X and got rid of all the PPC code. That is the whole point of SL - to refine it.
Leopard isn't going to stop working for you the day Snow Leopard comes out. It will run the same tomorrow as it did today and yesterday.
Sell your old hardware and use the money towards something new if you have to run Snow Leopard.