I personally think it can only go from 1.8% (right now) to about 2.4%, 2.6% if we're lucky. The reason is Microsoft already achieved a monopoly lock on the operating system market. When they finally realize that they are crazy making Windows 8, they could just go back to promoting Windows 7 like hell, like they did with Vista and XP. And there is a critical lack of content: Netflix, DVD playback, illegal codecs, exotic web plugins (Shockwave, Unity). Plus there is fighting within the Linux community, if you go in the Arch IRC channel and tell them you use ArchBang, they would give you a hard time. And there is a lack of standardization (.deb .rpm .tar).