Right after I blogged yesterday about the value of UI customization I came across this post by Ian Blyth on how Systems Center Operations Manager console only allows you to set the agent proxy one server at a time. Ian writes how painful it is to manage multiple servers and how he has to use workarounds such as command-line or a separate utility by Boris Yanushpolsky (a friend of mine by the way: hello Boris! ;))
In the end of the post Ian mentions that he only hopes OpsMgr SP1 will bring the change.
By the way, thanks to Rob, PowerGUI already has a pack for Operations Manager which provides for bulk operations and is fully extensible so you can have UI for proxy agent management and much more without waiting for Microsoft to provide every possible option you need in some SP.
Will that help you, Ian?