Well I think I know the answer to my own question but I wanted to confirm with others. I'm in the planning stages for Federation and had thought of rolling out an array of proxies: 1 public IM connectivity and 1 Clearinghouse configured. Then I got around to thinking how my pool would communicate to them if they were load balanced. I could not figure out how communications would work if my LCS server routed wrong traffict to one or the other. How would my Clearinghouse route communications destined for MSN.com user...

Got a sinking feeling in my stomach when I thought of this. Now I read this in the SP1 guide for federation: "A default route to a clearing house cannot coexist with IM service providers on the same Access Proxy or array of Access Proxies. If you want to configure a working default route to a clearing house, you must remove all entries from the IM service providers table. If you have configured an existing default route on an Access Proxy, you must also remove all entries from the IM service providers table in order for that route to be functional."

Am I out of luck if I want to setup both a clearinghouse proxy and then another Public IM proxy for my environment???