Well, consider the following: your Civic's engine was designed with far more lax emission controls than in 2006. Given today's much stricter emissions certification and the fact the L15A VTEC engine dates from around late 2002, Honda did a pretty good job getting this engine to meet current EPA/CARB emissions standards.

I expect when the Fit has its full-model change (FMC), the primary engine for the US-market model will probably be a lower-displacement R-series engine, especially given the compact size of the R-series engine block and the modern SOHC i-VTEC valvetrain design. It'll probably be rated at around 117 to 120 bhp (SAE 08/04 net) and get ULEV Level-II emissions certification.