I used to be, but I'm coming round to the view that with all of the big commercial players, now including Microsoft, pushing heavily towards services and "the cloud", the decay of their traditional desktop offerings will create an opportunity for a Linux-based (or other OSS) platform to become relatively attractive a lot sooner.

This is partly about the operating system itself, but it's just as much about the applications. Building a direct competitor to MS Office is something few sane people would consider attempting, given market conditions and the effort required. Implementing a native desktop competitor to a typical on-line "office suite" today is something a small team of smart people could do, reaching functional parity within months, and there is nothing close to a dominant incumbent in the market yet, nor is the user experience for these web applications anywhere near as polished.

In short, as they lower the barrier to entry and open up the market, they make it easier for Linux-based applications to catch up. They also make it more attractive for someone to invest significant resources to polish up those applications as a commercial venture.