A single OStatus-based PHP app, marketed well, and with an easy install path, might make widespread adoption of OStatus more likely. It could even piggyback on existing WordPress installations as a plugin. Then, anyone with a self-hosted WordPress blog would be able to host their own status updates under a fixed path appended to their existing blog, such as example.com/status/. It also offers the potential for anyone with a WordPress blog to become a provider of status pages for people who didn't want to host their own (because WordPress has an inbuilt user registration system), which could create a distributed, portable network with no lock-in.
There are supposedly 60 million WordPress installations out there. These users already understand the value of owning and hosting their own content. That's an awful lot of potential to kickstart the uptake of a distributed social network, and I'm not sure that anyone's thought to exploit this yet.