Once artificial intelligence reaches human level, there will be a positive feedback loop that will give the development a further boost. AIs would help constructing better AIs, which in turn would help building better AIs, and so forth.

Also, the marginal utility of improvements in AI when AI reaches human-level would also seem to skyrocket, causing funding to increase. We can therefore make the prediction that once there is human-level artificial intelligence then it will not be long before superintelligence is technologically feasible.

A further point can be made in support of this prediction. In contrast to what's possible for biological intellects, it might be possible to copy skills or cognitive modules from one artificial intellect to another. If one AI has achieved eminence in some field, then subsequent AIs can upload the pioneer's program or synaptic weight-matrix and immediately achieve the same level of performance. It would not be necessary to again go through the training process.