Today I looked at Google Images for pictures of the N Scale range, and I came across this picture: http://fav.me/ddjduxc
Hopefully that forms a link. If not, you can copy and paste it into the internet, and I believe it'll take you where I hope.
So I decided to measure the length of where the sleepers are on Thomas and the troublesome truck to get a wheelbase length (for the truck) and overall length (Thomas). Here are the measurements for those two things.
Truck Wheelbase: 20mm + or - 0.5mm
Truck Length (w/out buffers): 36mm + or - 0.5mm
Thomas Length (w/out buffers): 45mm + or - 0.5mm
Measurements of OO Scale Bachmann Thomas Products
Truck Wheelbase: 40mm
Truck Length (w/out buffers): 71mm
Thomas Length (w/out buffers): 90mm
Assuming that the N Scale line is at 2mm scale (1:148 Scale), the measurements are very close to what they would scale to in OO, and how Bachmann's current products are scaled. In real life, the truck scales very closely with it's counterpart, except for it's 10 foot wheelbase (although correct for the show [Classic Series], the real wagons have a 9 foot wheelbase). In conclusion, I believe the N Scale line is going to have British N scale, er, scaling.
Another interesting thing to note is that, although Annie and Clarabel have CGI scaling, Thomas is still the same size as his Classic Series (Series 1-3 or 5) counterpart. In the CGI series, he shrank, and is only supposed to be as long as the trucks. I cannot speak for Percy, though, because I don't have an OO model of him. It'll be interesting to see if James ends up with CGI scaling or not.
Keep in mind these are estimates, although I hope this helps give a picture of what we can expect of the N Scale range. Sorry if the post formatting is a bit strange.
We already knew it would have British N Scale scaling.