I would like to know if the most recent Apple Macs have the EFI firmware up to date to boot Windows through Boot Camp.
Why not? Any Intel-based Mac can use Boot Camp to install and boot Windows. Only really early Intel-based Macs needed an EFI firmware upgrade.
The only restrictions (currently) are: Boot Camp 4.0 can't boot Windows XP and Vista, and it can't be used on Macs using a Mac Pro RAID card or software RAID.
See more on the Apple Boot Camp support site.