Yes. The 64-bit version of Windows 7 can be installed with Boot Camp on Intel Macs with a Core 2 Duo processor. As of the time of this answer, full support for Windows 7 had only been out for about 8 days, so make sure you have installed the latest updates from Apple before installing.
Yes, and they have for years.
64 bit support Hardware is minimum and 64 bit server support hardware is maximum.
Only Windows 64-bit operating systems can run 64-bit applications
All 64 bit versions of the OS's.
x86-64 is 64 bit processing on 32-bit architecture,not to be confused with true 64 bit-processors like Itaniumhttp://en.wikipedia.org/wiki/X86-64
The Ubuntu/Kubuntu kernel is configured to support 8 processors / cores in 32-bit and 64 processors / cores in 64-bit.
You need the hardware that can support both 64 bit computing as well as the software (most especially the operating system) that can run on a 64 bit platform.
Yes, and given the lack of 64 bit software support, probably better, and you can use unsigned drivers.
Yes. However, Mozilla does not officially support the 64-bit build on Windows yet. You can find some downloads for unofficial 64-bit builds for Windows in the Related Links section.
64 bit
Yes. The mobile versions of the Pentium Dual-Core, and Core2 Duo support 64-bit operating systems.
PCI 2.1
It is almost always better to install the 64-bit version of an operating system when the processor supports it. The only reasons to install the 32-bit version of Windows 7 would be if your Mac only has a 32-bit processor (only the 2006 Mac Minis and early 2006 iMacs had 32-bit processors), or if you need to run 16-bit Windows or DOS applications.