> Can you now implement the letter 'i' to act as an 
> imaginary unit? Is that possible?

Yes, it's possible; however, the developers do not think it is worthwhile.

> If it's possible in MATLAB, why not have both 'j' and 'i' 
> in Python as well?

Python does some things differently that MATLAB.  One design
choice is to avoid global configurations (such as number of
places displayed in a float) because modules written by
different people make make different assumptions or may
compete for a preferred setting.

Let's try to end this thread now.  It's a bit of no-win
situtation.  None of the core devs see enough possible
benefit to warrant the disruption it would cause.  Years
of Python being used in the scientific community has shown
that the current use of 'j' has not been a problem.