HP has release patch QTP_00699 Support Testing on 64-Bit Applications (For Specified Technologies) on QTP 11. Below is a quote from the patch readme.

================================================================================

Patch Description and Technical Details

This patch enables QuickTest to test 64-bit applications developed using the following
technologies:

1. Standard 64-bit Windows applications (C/C++ applications)
2. 64-bit .NET (2.0, 3.x, or 4.0) Windows Forms applications
3. 64-bit WPF applications
4. 64-bit Java applications

Note: This patch does not provide support for Web-based applications, such as .NET WebForms,
WPF XBAP applications, and Java applets.

Supported 64-bit Operating Systems:
Windows 7 64-bit
Windows Server 2008 R2

Note: QuickTest Professional 11.00 is a 32-bit application.

More than likely QTP 11 will support testing on 64-bit application, but it will not be an out of box support, it might come as a patch afterward.