For the slow Management Console that people are experiencing, I find that this is do to the the store service not releasing memory in a timely fashion. The server is essentially starved for RAM for all other processes. This fix for me was to manually configure a limit on the amount of memory that can be consumed by the store service. The happy point for me seemed to be around 1GB of free RAM on the server.
This makes RDP and EMC very fast as there is always free RAM available. Maybe would be a fix for those with a slow EMC.
As for silverlight in EMC? Please do NOT do this. I also vote for having ALL powershell functionality in the EMC. The 2007 EMC seems like an afterthought that was thrown together at the last moment. I STILL need to use Exchange System Manager to get a quick summary of mailboxes, their number of items and storage size. I know there is a powershell command for this somewhere, but when you have to wear 10 hats in a smaller company it is just not practical to go looking for the correct powershell command.