>Are there any plans for this?
I'll let VMware answer the plans portion of your question and provide an alternative.
You can run Microsoft Virtual PC on OS X/PPC and install either a small Windows or Linux image with the VMware Server management tools and this would not be so bad for managing your VMs. I ran Microsoft VPC for years successfully on a PowerBook G4 as a VPN+RDP terminal. Yes I see the irony of running a Microsoft (nee Connectix) product to manage VMware Server. Microsoft VPC is the only commercially viable x86 emulation product for PowerPC - or you could also try going down a Bochs route. You can get VPC very inexpensively on eBay with everyone switching to Intel.
You can also enable VNC-level access to VMware Server machines and use a VNC Client for OS X (PPC) to access those machines. You can not power-on a machine this way but if the machine is on you can control the KVM. Just to clarify the actual guest VMs do not need VNC installed. The VNC I'm describing is a console feature built into VMware Server. There is more information on this option in the VMware Server forum.
Finally, iirc, the VMware Server console runs over X windows. You can install/enable X11 for OS X and open up your display (xhost+) this way you can run an X server on your Mac for the VMware Server gui. This would not work well over the Internet but would be fine on a LAN.
You have a lot of choices for managing VMware Server from a PowerPC machine hopefully one of them will appeal to you.