I really don't think we need exotic new technology to get good response and decent top end. There's a LOT of basic engine developments that Subaru needs to catch up on before they need to worry about fancier turbo designs.

laser clad valve seats for better flow than seat inserts like we currently have plus better head cooling.
Taper squish -- better off-boost / low-boost performance
Direct injection -- better det resistance would allow higher CR, which would yield better fuel economy for any given peak power on current heads.
Couple those with a low mount turbo like on the new LGT (if twinscroll, then that's a plus) and an FMIC that runs from bottom to top. Exhaust manifold becomes FEET shorter, and you get short piping like a TMIC, with FMIC advantages.

Now cash in that added response and off-boost power by shrinking the 2.5L design to a 2.0L bore, but keep the 79mm stroke for the spool and response the longer stroke provides. The result should be a significant MPG boost with a torque curve much like a stock 2.5L in the current WRX.

I know the big numbers are what people want, but the reality is that Subaru needs to drastically improve it's fuel economy to be viable in the US in the not so distant future. Their bread and butter don't meet future standards. The future is not going to be seriously more powerful engines than we have today, but finding ways to maintain or only slightly reduce power from current models while significantly improving MPG.

The current EJ engines are really long in the tooth. As much as I like how easy it is to swap most parts around, I think it's time for the Phase 3 EJ series with some significant changes.

 

Its actually the exact opposite. Its sequential so its the best of both worlds. It should spool very fast (well on the 6.7L ) and have big power potential.

On my year powerstroke it came with a Garrett variable vane turbo that was basically a really huge turbo that had vanes that would move and re direct exaust gases to help spool. That turbo is one of the reasons the 6.0L powerstroke (my year) made more HP and more TQ than the older 7.3 powerstroke. When the 6.4 powerstroke came out it came with a dual turbo system that basically bolted two turbo right againt each other, but the power pontential was pretty obvious when guy who modded the 6.4 were making BIG HP and TQ when compared to the 7.3 and 6.0. So Im assuming that the new 6.7 is taking the lessons learned from the years past.

The new scorpian 6.7 sounds like it should be a pretty nice motor and the 6 speed auto thats bolted to it (6R 140) is supposed to be the best auto ever made year to date (better than the fames allison 1000!) but time will tell it is a complete new motor and tranny design.

Diesels rule!!

 

Interesting you should mention that...

 

oh snap! what info do you have regarding the next gen motors?