It's expected this cycle that Multiarch will provide superior 32-bit compatibility for any packages that previously required ia32-libs, as well as a scalable way to add compatibility for other libraries going forward, removing one of the main pain points for running 64-bit by default. Adobe has just released a supported 64-bit version of flashplugin, removing one of the main causes for users to need 32-bit compatibility on Linux anyway.

At the same time, the availability of UEFI only on our 64-bit images gives another compelling argument for running 64-bit instead of 32-bit, offering features like a fast UEFI boot instead of a slow BIOS POST and possibly secure boot capabilities (or possibly, the need to use UEFI to be bootable at all on certain secureboot-enabled hardware).

Should we switch to promoting 64-bit ISOs by default for 12.04 (on the website, in pressings, etc)? What other blockers remain?