One thing I would like to see happening, is a process for the update to handle itself.
There are very few components that have this feature, but it is both a time saver, and makes me less nervous of upgrades.
I am thinking of a system like for example Virtuemart uses, where you click a couple of buttons, and it all does itself.
I know upgrading !JoomlaComments is pretty standard etc, but a feature like this would be great.
Just a thought.