I'm not going to link to the thread at TBP nor will I quote it. It's the one where Phil Masters (of Steve Jackson Games) got a ban for explaining what the disadvantage "slave mentality" means in Gurps.
In that thread, he basically says there will not be a 5th edition for Gurps, unless the RPG market drastically changes, and the popularity for Gurps increases. It's not really a surprise, but hearing it from Phil makes it real.
What I find hard to believe is why they won't Kickstart it. The diehard fans alone would fund it, assuming it did not have an astronomical funding goal. Throw in a bunch of 4th Edition PDFs as stretch goals and it would skyrocket. The Dungeon Fantasy KS made $176,450 over a $100,000 goal, which isn't a spectacular success but it's a success nonetheless.
As a start, they could simply make a new Gurps Lite, which is something we've wanted since the beginning. Something that could appeal to D&D players who are looking for more realism or grittiness. There's definitely a market there, as evidenced by OSR games that try to do exactly that.