The default parameter set for Get-Process accepts -Name by position.

Maybe it's just me, but I forget this all the time, and expect Get-Process 1234 to work.

I think we can make it work in a reasonable way too. If Name is a positive integer and we do not find a process by that name, search again assuming it was a ProcessId.

Edit: instead of making this work (which might not be a good idea always) - I like the suggestion from @rkeithhill to give a better error message.