I raised a case with Microsoft (being a Gold Certified partner helps:)). Here is the response
Thank you for contacting Microsoft Partner Pre-Sales Technical Support. It was nice talking with you. This is with reference to subject above.
Non Decrement Case has been created for your reference: Case Number# SRSXXXXXXXXXXX - SQL Server 2008- Multiple Queries
Please take a moment to review the information and contact me with any comments you may have.
Product:
SQL Server 2008
Query
Multiple Queries
Solution:
1) Is SQL Server Management Studio shipped with SQL Server 2008 64 bit , also 64 bit?
Ans:
SQL Server Management Studio is a 32 bit application
Runtime Compatibility
SQL Server Management Studio 2008 runs in WOW64 mode on 64-bit clients. Because of this, the 32-bit version of SQL Server Compact must be installed to use the tools available within SQL Server Management Studio
http://msdn.microsoft.com/en-us/library/cc835497.aspx
2) Is it possible to directly edit deployed SSIS packages from within Management Studio?
Ans:
Currently you cannot load a package from Mgt studio for editing. From Mgt studio you can see what’s running, what’s stored, and can execute a package but not edit.
Ref: http://social.msdn.microsoft.com/forums/en-US/sqlintegrationservices/thread/9cc6a819-e7b5-40a2-b5b6-0957118ffed7/
For more discussion please let me know we can have conference call.
3) Is there a 64 bit version of Business Intelligence Development Studio?
Ans:
Business Intelligence Development Studio, the 32-bit development environment for Analysis Services, Integration Services, and Reporting Services projects, is not designed to run on the Itanium 64-bit architecture and is not installed on Itanium servers.
Ref: http://msdn.microsoft.com/en-us/library/ms173767.aspx
Raj