The latest tubeless tech

On the tyre side, tubeless tyres are more airtight and more uniform than they were a few years ago - making installing and sealing tyres easier (and more consistent). UST never quite caught on, but in many ways the tubeless-with fluid is superior to the fluid-optional UST approach.
Tougher sidewalls (like Mitas Textra) help prevent cuts.
Better puncture protection layers (like Bontrager SE tyres) make the overall tyre more durable without making it DH heavy.
Beefier carcasses lend DH-like durability to slightly lighter tyres (Maxxis Double Defense and Schwalbe Super Gravity casings).

Inside the tyre you can place foam and sealant.
For the foam side of things are options ranging from expensive (Huck Norris at about $100 per tyre) to really expensive (Schwalbe ProCore is about $200 per tyre - and isn't foam as it is a second tyre with its own tube, or FTD, which is a shaped foam insert meant to stop pinch-flats and permit running on zero air when necessary - as used by Aaron Gwin). Check out the VitalMTB website review of flat tyre systems.
Sealants continue to improve.
Stan had a race specific sealant he provided to sponsored athletes that has now been made available to the general public. Race sealant has more particulates in it to seal larger holes but unfortunately it dries out faster.
Orange Seal has race and endurance product. These two are directly analagous to Stan's sealant except that they both last somewhat longer than the equivalent Stan's version.
Steve Pete is releasing a sealant soon - complete with blue glitter as the particulate component - that is not supposed to dry out in the life of the tyre. It uses non-volatile solvents so it cannot evaporate out through the tyre wall. If it works, and it doesn't end up too expensive, it will become my sealant of choice as I'm really tired of Stan's drying out so often.

I used to have loads of tyre issues off-road. Back in the 90s it was tyres spinning on the rim and tearing the valve stem off the tube. BeforeI went tubeless I got lots of pinch flats. Now I have destroyed rims and the tyre remained inflated. Tyres last longer and work better too.