The BMW i3 and i8 concepts have been revealed online, but BMW i is not done. According to Scott26, the BMW i4 and BMW i5 are the next models to come out from BMW i.
The BMW i4 will be based on i3 technology, but fit into a small two seater sports car (think smaller and more affordable i8). The BMW i5 will be a mid-sized four door coupe/sedan, using the power train from the BMW i8. Concept versions will come sometime after the 2013 launch of the i3 and 2014 launch of the i8, but actual production is not expected until closer to the end of the decade.
BMW AG has officially filed a registration for a new trademark and logo for their project-i vehicles such as the electric Megacity car and hybrid Vision EfficientDynamics sports car. The trademarks i1, i2, i3, i4, i5, i6, i7, i8, and i9 have also been registered.