XCOM 2 [official site] is a hugely exciting prospect (so much so that I'm genuinely grumpy about the delay), but XCOM and X-COM are so very different things by now that it's unlikely to slake anyone's thirst for a true-blue, Gollopy experience. Fortunately, sounds like we might also be in for a sequel to unofficial X-COM spiritual sequel Xenonauts [official site], 2014's Cold War-set alien invasion strategy title.
The 2014 game was well-received (and even has its own, ongoing, spun-off community edition: the student has become the master), and now devs Goldhawk Interactive are on the verge of deciding whether to make a second one or not. Two more X-COM follow-ups, each exploring a different facet of the game, then: the cosmic ballet continues.
"The chances of us making Xenonauts 2 as our next game are better than even," wrote project lead Chris England on the Goldhawk forums. "The response to and feedback given on a potential sequel by the community has been remarkable and has gone a long way to convincing us that it would be a good idea."
Seems like there's been a reasonable amount of drawing board action already. For instance, they're planning to move from 2D to 3D for the next game, if they can make it work. "Our biggest concern regarding Xenonauts 2 is whether we can create a workable 3D art style - this not only has to look good in 3D but ideally will also reference the 2D sprite style of Xenonauts 1."
They also talk about redesigning Xenonaut's aliens "to make them more interesting, both visually and in terms of the core mechanic for each race", and emphasise that they want them to look more alien than last time around.
The air combat is in far a major overhaul, with Chris England saying of the first game that "I don't think it really lived up to its potential" in that respect. There's a long breakdown of his current thinking for the mode in Xenonauts 2 here. In short: quicker, less micro-management, more variety.
There are a few more bits and bobs here, including some creature and level concept art.