Most of the latest programs, that run decently on our PPC machines were universal binaries from 2009/10 or even later. Some developers have updates to their PPC-software, so files and databases can be handled on both PPC and Intel-versions (like MS Office, DEVONthink etc.)
I also agree that to emulate "full sized" Intel-Apps on a PPC would be beyond capabilities of even the fastest PPC.
As
@bunnspecial said: VirtualPC7 with WinXP is a hassle on a Quad-G5. On my PB-G4 it's even slooower (thanks Gavin's hint, there's "Win Fundamentals" to do a much better job). Same would be any intel2PPC-emulator, I guess.
As for me, the biggest challenge is to keep the PPC connected to the Cloud. Any advance in keeping native Clients alive or univesal (S)FTP etc clients like Cyberduck adapted to the latest two-step-autentification of major Cloud-services would be a big step forward.
Maybe we could make a "PPC-Croud4Cloud"-funding campaign (developing time is money) to bring those features to Cyberduck!?
In the meantime I use my universal-hub (aka iPhone6s with iFiles) to connect all of my machines with all of my cloud-services
An iPhone 4s or later would do the same job - even without phone-contract/SIM-card just by Wifi-connections.