I think Putin is just biding his time, knowing Obama won’t make anything but noise, while the economy reacts and rebalances, so as to minimize the economic impact. He can afford to lose 20%, then gain back 10, repeat til he has what he wants and then gain it all back.
American economic sanctions are pretty trivial at this point, and the Europeans, who have more bilateral trade with Russia, for the most part seem to be ignoring the EU sanctions protocol as well.