[brudgers]

Depends on what you mean by "major". And for most meanings it probably won't. Partially because languages are like startups, only a very few get massive, most die quickly, and some turn into lifestyle businesses. Partially because Go is just another alternative for many web and general programming tasks and what differentiates it as a language is often not a high priority and what differentiates its tradebase of experienced programmers, smaller size, often is.

If the JVM, .NET, Browsers, Rails, or heaven forbid Python are options the business case for Go is hard to make. Their tooling is mature and robust across platforms because the technologies are mainstream. The programmer tradedebase is large for the same reason. Go lacks attractive tooling for mobile ecosystems. In 2015 that would not appear to bode well for general use, all levels of the stack matter.

There has to be a compelling reason to trade that away for Go. Those reasons exist, but only sometimes.