Brought up on the Ubuntu development list yesterday was a proposal to disable Wubi installations from Ubuntu 12.04.
Wubi is the less-common way to install Ubuntu, which allows for installing Ubuntu Linux as almost like an ordinary Windows program, where the disk doesn't need to be re-partitioned or anything but it's installed from within Windows. Up to this point Ubuntu's Wubi could be utilized from either the standalone installation media or from the official Ubuntu ISO, but this proposal by Canonical's Rick Spencer is to do away with the Wubi support from the Ubuntu ISOs.
Under this proposal, Wubi would still be there to provide information to Windows users, but the installation option wouldn't be exposed unless downloading the Wubi Windows executable.
The reasoning for this change, according to Spencer, is that maintenance and enhancements could then be done outside Ubuntu's normal development cycle, a reduction in Ubuntu QA work, better overall 12.04 quality, and not being stuck with a poor user-experience on the CD.
Also complicating matters is Microsoft's Windows 8. With Microsoft's Windows 8 to be released by year's end, the boot system is expected to see an overhaul, at which point Wubi may not work.
The mailing list discussion in whole begins with this message