Current Japanese Domestic 1.5L Fit has 81（kW[PS]/rpm）/5,800 and 143[14.6]/4,800 （N・m[kg・m]/rpm.
If the above # (1.5 L VTEC - 105 HP - EPA rated 32/37) is ture it's lower than or equal to current version after adjusted to new US HP measuring standard (which most Honda gets lower hp).
I think the US Fit will be the completely new version and should improve in power and economy and get little larger in size.
Japanese Fit compete with Corolla (in total sale #) which ranked #1 for long, but Fit stealed it recent years. (this is pretty big deal since Toyota dominate Japanese market all time. They kept more than 50% car market share for long in the past.) You can imagine Fit is very important car for Honda in Japanese market. So, I believe the newer version should get substantial improvement to compete with up coming new Vitz/Yaris, Corolla and others next 4 to 5 years. It will be five years by next spring since Fit intro, and full model change is just right timing.
Toyota Yaris for US market will have up to 40 mpg and 106 Hp according to here.
http://www.toyota.com/vehicles/future/y ... TURE_YARIS
Even current US Corolla get 38 mpg.
It's not all about # but hope Fit will do better than that. 1.5L base Fit should do better than 35 mpg.
At least one Japanese magazine speculate that the new Fit will be little wider with 1300cc Sohc Vtec and 1500cc Dohc Vtec and may have 1.7L version too.
I am hoping Honda will introduce Fit Si (even better with Type R) and hybrid probably in second or third model year. It will be hard to choose... The best one would be Fit Si hybrid. It's not gonna happen but nothing wrong with deaming it. We are talking about the company with "The Power of Dreams" slogan.
I think Insight is really the car created by the power of dreams.