TA2 should be coming soon:
http://www.pcgamer.com/chris-taylor-you-can-use-your-imagina...
That was 2013, so perhaps E3 this year we may see an announcement. Four years is usually standard for big projects.
In the mean time, SC:FA on FAForever is your best bet.
I hadn't heard the news, that is terrible. It basically crushes any hope I had for TA2 being good.
Figured they'd have just given CT free reign and had TA2 use a traditional retail pricing model ala Master of Orion, a Wargaming Labs project. It's still possible that could happen, but doubtful.
https://www.kickstarter.com/projects/659943965/human-resourc...
GPG went under right after that campaign (October 2014). Technically they got bought out, but who knows if the new owner wants to make the same kinds (or quality) of games.
I'm of the opinion that another CT RTS would be a project of 50/50 potential for TA fans. I love SupCom only a little less than I do TA, but I'm not a big fan of SupCom 2. On the other hand, some other old TA vets weren't big fans of SupCom, only to find themselves really liking SupCom 2. I never played PA, but I'm pretty confident I would be meh on it.
People like to trash Planetary Annihilation but it's not really deserved. Yes, it doesn't scratch the TA itch as well as one might wish but it's a decent game in its own right.