I'm finding a number of road blocks on our Domain that prohibit consistent access by PShell Scripts, commands etc. We have many 2003 servers (hundreds) along with 2000R2 servers. How are people dealing with installation of different versions of powershell, execution policys, RPC and other connectivity issues trying to manage servers across the domain.
For the most part, it depends a lot on the type of organization you work for. If you can't maintain a consistent, up-version level of Windows, then you're simply going to have to deal with inconsistency. You try to write for the oldest version of PowerShell you can, and you keep in mind that not every version of Windows supports as much PowerShell manageability. Win2003, for example, has relatively little PowerShell goodness compare to, say, Win2012.
Being able to deal with inconsistency is pretty much a job skill, now. You have to acknowledge that you'll never have the 100% consistent environment we all dream of, and so you have to develop skills and techniques that accommodate the inconsistency. Those techniques will differ across every organization, since everyone has different tools, different organizational priorities, etc.
Execution Policy can be managed by GPO.
RPC is a firewall thing, and can likewise be managed by GPO.