Companies do this all the time, especially European. For instance, in the US the SLS AMG Black Series came fully loaded except for B&O stereo. In Germany, the standard features got cut and were offered as individual options. The base being more expensive (even taking taxes, conversion rates, etc into account) than the fully loaded US version.
I've already seen US i8 marketing literature for BMW sales staff and everything mentioned there is standard. Even BMW's offical
spec sheet has 20" wheels standard.
BMW's head of marketing for the "i" brand is on record stating that paint, interior, and wheel design would be the only choices and that customers would be "pleasantly surprised by the pricing." I think they know going higher than $135k for a 1.5 liter 3-cylinder hybrid in the US would be asking a bit much...let alone another $20-30k.
They can (of course) change their mind but I don't think they would after announcing a price and being so confident about the "value" proposition.