[moe]

I can see that executing some commands over a set of hosts at the same time could be useful

for h in $hosts; do ssh $h "my command"; done

As for deploying from staging to production servers, it sounds more tidy to build proper packages to deploy in staging and test before deploying the same packages to production.

Amen.

[prodigal_erik]

dsh is worth looking at. It's essentially a for loop that runs ssh, but it can also get named groups of machines from config files, run them in parallel, and prefix output lines with the machine they came from.