Mistakes: Depends on the outcome of efforts to try to reduce answering errors. If self introspection works, months.

More context memory: Weeks to months. There already are papers that set up the groundwork: https://arxiv.org/abs/2302.04761 . Searching the past log for this same session (past our token window) is easily integratable with the toolformer architecture.

There are also alternate architectures that may also enormously increase the window.

AGI : it is possible within a few years. Whether it happens depends on the trajectory of outside investment. If Google and Microsoft go into an all out AI war where each are spending 100B plus annually? A few years. If current approaches "cap out" and the hyper diminishes? Could take decades.

Singularity: shortly after AGI is good enough to control robotics for most tasks. So shortly after AGI probably. (shortly meaning a matter of months to a few years)