Wubi must overcome some hurdles for Edubuntu

From 12.04 you will be able to install Edubuntu with Wubi. There are a few hurdles to overcome. The first is that Edubuntu requires a DVD image to install, and Wubi has built-in checks to prevent this - the ISO must be < 900,000,000 bytes (or 858MB) .

These same checks are what prevents users from installing a normal desktop CD image from a USB stick. These days USB sticks are generally large - in fact the Ubuntu download site states that a minimum of 2GB free space is required when creating a bootable USB.
But the way Wubi works is to copy the entire USB partition as the 'ISO' during the installation, and following that it performs the 900,000,000 byte check, and fails.
There is another danger because the USB partition is copied without any space checks. So imagine if you have 10GB space left on your hard drive, Wubi proceeds to install, but then tries to copy a 16GB USB stick partition onto that same hard drive. (That can only end badly). And even if you have enough space - it's going to fail the size check anyway.

Why is this an issue? More and more users are using USB sticks as they are cheaper, readily available and much less hassle than CDs (bad burn anyone?). But even more importantly, there have been reports that the Ubuntu desktop CD ISO will be increased 750MB size from release 12.04 on. This rules out the use of standards CDs. You can still burn a CD ISO onto a DVD - that works because the ISO does not expand to the DVD size in the same way as with a USB partition.

Relevant bugs:
Edubuntu https://bugs.launchpad.net/bugs/913354
USB https://bugs.launchpad.net/bugs/461566

Wubi will support Lubuntu in release 12.04

Lubuntu
Coming with 12.04 precise pangolin, Wubi will support Lubuntu. Preliminary tests using the daily live CD and this wubi.exe are successful. Note you have to logon blind for now while bug 918401 is sorted out.

I found that Lubuntu ran very well on my junky old test laptop - while it was very sluggish with 11.10 Ubuntu. So Lubuntu might be a better option for older machines.

If you're going to be testing Wubi remember to use zsync to keep your test ISOs up to date. It's a great tool.

Other wishlist
It'd be nice if Wubi could install from a USB stick with 12.04 - since the desktop CD ISO is supposed to be around 750MB it won't fit on a CD so I expect many people will try with USB. Waiting on longstanding bug 461566.

Also, it'd be nice if some of the obscure error messages that have appeared since 11.10 could be replaced by human-understandable text. For example "WindowsBackend object has no attribute 'iso-path'". I suppose it's no better than 'Permission denied' being used indiscriminately, but I suppose we were used to that.

For the 'preinstalled image' install method, I'd like to see an easier way to override the kernel boot options for users with ATI or NVIDIA cards requiring 'nomodeset'.

From a personal point of view I'd like to have an installable Wubi migration gui app ready - but it's not looking like it will happen in time.