Dual Booting X86 and X64 In Retail Vista

[DCR]

I have read that the retail version of Vista will have all versions on one
DVD.
The version you install will be determined by the key you purchase.

My questions are:
1) Will the one DVD have both X86 and X64 versions?
2) Will one have to purchase separate keys for each version?
3) If one key will unlock both versions, can one install both
versions in a dual boot configuration?

I have a dual core X64 AMD processor (I understand only Ultimate -- for
consumers -- will support 2 Processors).

It looks as if some of my hardware will not have X64 driver support.

I would like to have Vista X86 for full hardware functionality, but I would
also like to have Vista X64 to take full advantage of my processor (and
memory -- 4 gB) and X64 capable programs.

 

[John Barnes]

My questions are:
1) Will the one DVD have both X86 and X64 versions?

The license says yes.

2) Will one have to purchase separate keys for each version?

License indicates no, but states

3) If one key will unlock both versions, can one install both
versions in a dual boot configuration?

That only one version is authorised at a time.