I wish more web services provided opensource versions (Service-as-a-Software). Large orgs would still pay for service contracts even if they self host, and just having the option makes everyone more likely to invest on top of your service.
Chat at "indie scale" is fairly easy. 10-20k concurrent users fit into one or two machines with off the shelf software (ejabberd) with minimal expertise. 1k-2k concurrent users could easily be done in almost any stack.
If you're doing more than 20k concurrent users, odds are you can afford to hire someone to scale up or build out a team to do it, or find a 3rd party service and pay them to host your chat.
The author works for mozilla, and firefox is a common theme on his blog. I think it's for regular readers of his blog to understand the practical impact (readers he assumes care more than average about firefox).
Do we need significant software changes to take advantage of the new power? Are the TFLOPs somehow not directly comparable?