Package: debian-installer
The debian 8.2. netinst image is missing the 9p FS driver.
It would be great if d-i had that and the ability to mount a virtio 9p filesystem to fetch the preseed file from. This would make VM preseeding much easier, as all that an installer will have to do is to expose a directory with the preseed file.
I'm not sure if the floppy:// source supports that, as I can't test it without the 9p driver. If it does then all that's needed is to include the 9p driver.