Yay! Visual Studio 2010 RTM is shipping today! If you have UML models, Sequence or Layer diagrams created in Beta2 or RC that you want to upgrade to RTM, then I have good news. The model upgrade tool has been updated to support RTM.
Note that there's actually only one format change between RC and RTM. The only change was in the Work item links from our diagrams and model elements. So if you used work item links in your RC models, then grab the tool and upgrade them. If you have no work item links, then sit back and relax. Your models will open and work just fine in RTM, without running the tool.
Now, if you have Beta2 models, then the tool is definitely needed. There were a number of changes between Beta2 and RTM, and you should run the model upgrade tool to enable your models to open in RTM.
You can find the tool here:
Please let me know if you find any issues with the tool, or if you have other questions regarding upgrades!