I do think there is a whole lot of wishful thinking about the weight and price of the 135i. IMHO, the likelihood of a 3200 lb., $35,000 fully loaded 135i are about slim to none.
This is BMW remember? They nickel and dime you with every option (hello!? fold-down backseat costs EXTRA). $40K will not be out of the question for a loaded 135i.
And given that it has the same engine as the 335i and does not have a carbon fiber roof, you can expect the 135i will be a 3400-ish lb. vehicle.
So for a few grand less than a 335i you get something slightly smaller, different styling, 100-200 lbs. lighter, only available in a coupe, but with the same engine.
For me, I like the 1-series styling and I don't need a sedan, so I'm game. :-)