Not much is changed. A lot of the big manufacturers are worried about safety issues and have not jumped into integration.
Rheem offers its own WiFi module, but IIRC it was pretty limited in what you could do with it.
GE has done the most, and has an IFTTT channel for its Geospring line which some community members have used for SmartThings integration.
There are a number of third-party add-ons which incorporate just a plain on/off switch, typically a WeMo insight, but I’m not convinced most of them are really a good fit to the use case or offer any more than just adding an appropriately spec’d relay.
Probably the newest thermostat type add on option is the Tado. I’m not sure why, but reviews in the UK have been much better than reviews in the US. Anyway, @Fuzzyligic knows a lot about the brand.
Hopefully others who have experience with different options will add more.
Most of the threads will appear on the quick browse lists in the community – created wiki with the HVAC tag, but it sounds like you’ve already looked at everything.