After some suggestions within Ubuntu artwork team mailing list, I came up with one more solution for "universal" Ubuntu DVD cover. This time it's even more simplified, and it's completely in aubergine/white color palette, like recent official Ubuntu sleeves are. Also this time it's done in Pictogram style, with circles all around, to make it more officialish and Ubuntu related. (Well, at least current Ubuntu visual identity is pictogram style oriented.)
For those who wants to put a specific version label on this cover, I will upload a psd file too, on spreadubuntu. So as soon as I do that, I will paste the links here.