Softcoder and Titi have spent lots of their time on making MegaGlest packageable for Debian GNU/Linux, which, for the most part, Ubuntu is a clone of. Ubuntu's "software center" is basically yet another APT frontend, but with (I think) hardcoded filters so you only get to see some packages but not others. I'm not sure which criteria they apply there, but I guess you'd first need to get the package into Ubuntu, which basically means getting it into Debian.