More what could a 4th ed look like
On thing I'd like to see in a 4th edition, and I'm sure people will say it's too complicated and break compatibility too much, is a doubling of all the point values for everything across the board:
By default, characters are build on 30*PL PPs
abilities are generally 4pp per rank
defenses are 2pp per rank
skills are 1pp per rank
advantages are 2pp per rank
powers, extras, and flaws have most of their current ranks doubled and flat costs doubled.
Now on the face of this. Nothing happens. Rank for Rank a prior edition char and a new edition character would look the same and the point cost for the new char is just double that of the prior edition char.
But, the bold parts of the list above are where the change becomes interesting. Every want to give a power a 1/2 extra or flaw? Every wish Presence cost less that Strength? You can more easily do this if there are more points in play. There are constant proposals to remove Dexterity and give free advantages for each rank of Presence. Instead, why not just change the cost of those abilities reflect their utility.
I'm not going to analyze all the parts of the game where some specific flaw should 3pp/rank or 1pp/rank instead of 2pp/rank. Or all the advantages that should be 1, 2, or 3 PP per rank. But just opening the design space up to this kind of tinkering could be valuable.
Re: More what could a 4th ed look like
Last time I saw an official response concerning this subject, it was said by staff that there were no plans for a 4th edition. I wouldn't even worry about it until that changes.