The price of fuel isn't going anywhere.
There's so much excess capability just waiting for oil to climb that will suppress pricing for decade(s). Australia is now coming on line as well with all the newer fracking technologies so yield out of massive oil formations in North America and Australia are a ceiling to OPEC manipulated pricing.
Why is this important?
Because it means that SUV sales and less than "eco" models continue to sell while econo isht boxes and sedans are suffering. Toyota is practically giving away sedans.
That means we're not going to see a MAJOR departure from the current power train.
Ford and GM joined in a new 10 speed venture which is part of these new efforts to comply with EPA incremental fleet averages.
I'd venture that Toyota wouldn't be far behind with an 8 or 10 (or 12) speed auto and new small engine, twin turbo or hybrid engines as the base/standard (like Ford's ecoboost+10R80 powertrain).
But that stuff has all been put on hold given the price of fuel.
Higher fuel prices would mean the 4Runner and Tacoma would HAVE to change drastically to stay in the segment. But with fuel prices depressed (outside of a major war or world calamity) there's little to no incentive for them to make any major modifications to the core of the 4R/Tacoma anytime soon. Especially with sales of gas guzzlers doing well.
