Fixing indentation would be the minimum what I would expect from StackOverflow (by fixing indentation I understand removing unncessary spaces as well as adding them when necessary, for example on if/for/while loops, nested XML tags etc.).
Of course, such features would require choosing the source language of code block - this is another feature that is missing. You can learn by heart
language: lang blocks, but it should be a menu option.
Of course, there are esoteric languages where space is a part of syntax, not formatting (Python AFAIK) so such feature must be optional and activated only by taskbar button.