According to tech news site Inquirer.net, Microsoft won’t support EFI booting for Windows Vista. No EFI booting means no dual-boot OS X/Vista Macteltoshes.
Speaking at Intel Developer Forum in San Francisco, Microsoft development manager, Andrew Ritz said that the same will apply for those wanting to support for booting Windows via EFI on systems with 32-bit processors…[The] main reason dumping the EFI booting was because there was it wanted to drive a move to 64-bit computing, Ritz said.
Well presumably this means no dual boot Vista/OS X macs _yet_; if Apple adopt 64 bit processors in (for example) the Power Mac's successor, then the bet will be back on again won't it? i.e. the only stumbling block for the moment is that the Intel chips used so far are only 32 bit, yes? In fact the Yonah is the only 32 bit chip in the new family isn't it?
Further to TheBoyKen's comments, aren't Intel replacing the Yonah chip used in the iMacs and MacBooks in about September this year? I'd heard they're replacing the Yonah with the Merom, a 64-bit chip part of the Core architecture platform. Will this means Macs using Merom will then be able to dual boot Mac OS X and Windows?
OS X Tiger already supports 64-bit components. I can't see how the boot process would hinder this. I would have thought that 64-bit computimg would be more hindered by the processor rather than EFI*, in which case Windows Vista not working on future Macs would be down to MS's decision in not supporting EFI. And this decision could be down to how much legacy code they would need to carry over. However, thet last point is just sheer conjecture on my behalf - I have no idea!
* - "FI is not part of the IA-64 architecture but by convention is required on all IA-64 systems"
* - http://en.wikipedia.org/wiki/IA-64