I know this means I'm quite late writing about it, but I only came about to learn about this Visual Studio.Net add-in quite recently and I wanted to study it for a bit before writing about it.
The BIDS Helper is an excellent extension to the BI Development Studio which comes with SQL Server 2005. Though my main uses for it are for the SSAS part of my BI project, the newly released version also has features for SSIS.
Among other features for SSAS, the BIDS Helper enables you to:
Validate aggregations – checking whether the calculations you defined in your cube with a collection of rules and best practices.
Run a dimension health check – checking whether attribute relationships hold true according to the data and whether the definition of the attribute key determines uniqueness.
Show extra properties – enabling you to insert more easily the description for the various properties.
Visualize Attribute Lattice – giving you a visual description of the connections between attributes in your dimension - what a way to clearly see your attribute relationships!
In SSIS I would mention the ability to create fixed width columns which is so much more comfortable than what you have in SSIS (and I have quite a few flat files I connect to as data sources in my project).
These are just a few of the features and they can all be a very big help in bettering your cube and more easily working with ETL packages. I owe a very big thanks to the people behind this tool and I'll be sure to follow for more updates on it. Go to the CodePlex site for the download.