Great news: Composite Application Block is out (CTP of course). If You think about flexible, connected UI - check this out: http://practices.gotdotnet.com/workspace.aspx?id=22f72167-af95-44ce-a6ca-f2eafbf2653c.
The next thing - I was quite happy to see new BizTalk MMC features, such as added features for configuring BizTalk Server like in BizTalk Explorer. Also nice possibility to setup alerts based on BAM views with necessary thresholds and monitor system behavior. In other words the full system monitoring cycle now is available - it should be much easier to detect technical (MOM) and business (BAM) related issues, debug if necessary (HAT) and bring back BizTalk server to the correct operational state (MMC).