This kind of makes Xgrid irrelevant, unless Xgrid has support for heterogeneous networks and fat binaries (and last time I checked, it didn't). Now you won't be able to offload compute-load onto the LAN unless all the workstations have the same architecture processor.

This is awful.

But if a PPC can build binaries to run on x86, why couldnt you have a network of a mixture of chips doing a Xgrid compile?

Surely if the OSX is the same, and the Xcode is the same (ie the same code, just compiled for different chips) then all we need is an update to Xgrid to handle the x86 'option'?

Xgrid doesn't need to support fat binaries. Fat binaries need to have support for Xgrid.

Future upgrades and new Xgrid capable binaries will either be fat, or will be stuck on one platform or the other, just like any other app.

Xgrid could be updated to check the platform the app is built for (or if it is fat) and make sure it only runs on one platform if it is "thin" however you should segment your grid if you are going to be doing this.