I'll get zero advantage by running Visual Studio or my applications on a 64 bit machine - all I look forward to is additional memory usage and incompatibilities with applications that won't install on 64 bit or run incorrectly.

If you do any of the following using Visual Studio (with any of the BI project templates):

- Run/test an SSIS package
- Deploy/process an SSAS OLAP Cube
- Run OLAP queries inside Visual Studio

....you'll get the benefit of the 64-bit server environment.