SharePoint Diagnostic Studio (SPDiag) has shipped!

SharePoint
Diagnostic Studio (SPDiag) has Shipped, and along with it SharePoint
Admin Toolkit (SPAT) v2 for SharePoint 2010.

This is a
very exciting day for our on-premise customers managing their own SP
installations. SPAT brings a crucial set of tools for managing and
pinpointing issues with SharePoint farms. With the inclusion of SPDiag,
the set of tools have become even more powerful.

New in SharePoint 2010 Administration Toolkit 2.0, the SharePoint Diagnostic Studio 2010 (SPDiag 3.0) provides SharePoint administrators with a unified interface that can be used to gather relevant information from a farm, display the results in a meaningful way, identify performance issues, and share or export the collected data and reports for analysis by Microsoft support personnel.

As someone who works on SharePoint performance and reliability by monitoring farms in production, this tool has been the most useful invention to me since sliced bread! You can use its nifty interface to connect to the logging database of a certain farm, see charts of the availability and latency percentiles for that farm, investigate issues such as extra slow pages, catch solutions that have design flaws that degrade performance, all within a friendly UI that will show you both the data from the logging database as well as the ULS logs. I was personally not involved in the creation of this tool, so I can honestly objectively say: it's brilliant! If there's any interest, I might post some blog entries about reports I like especially much, or think are useful. Let me know if you'd want to read more about this. 

There's also a post with a little bit more info on the SharePoint team blog by Bill Baer:

https://sharepoint.microsoft.com/blog/Pages/BlogPost.aspx?pID=971