From the Ars article:
Today the company announced that it would soon be removing SPDY support from Chrome. That’s because the Internet Engineering Task Force (IETF) has been working to update HTTP to produce HTTP/2, an updated revision of a protocol that has not seen any major changes since its introduction in the early 1990s. […] To reduce latency, it included support for multiplexing—making multiple requests and responses over a single connection, with prioritization for different requests—and for security, it makes the use of TLS compulsory.
Multiplexing and compression just make sense… but compulsory TLS? That’s quite a hurdle for the entire web to jump over. I’ve seen some arguments that there might be free certificates, but I wonder how that would be managed. Without having read much of the working draft, a natural question is how potential vulnerabilities in TLS would be handled over the next 15 years, especially considering recently discovered issues in SSL (POODLE, namely).
Regardless, I guess a server could always fall back to HTTP/1.1. It’s gotten us this far.