Scott Schnoll publiced an blog on the process of installing Rollup 1 on Exchange 2010 servers with DAG members. The process doesn’t really differ from existing Exchange 2007 CCR/SCR scenarios, i.e.
- Suspend replication;
- Move active copy/copies;
- Install the update;
- Resume replication;
- Reactivate copies when required.
You can find the blog article here.