I feel (or rather hope) we'll see more than that at some point. Being able to replace device-specific wall adapters would be a huge win. This has largely already happened for everything that needs 10 watts or less, but between that and things that actually need a lot of power (i.e. kilowatts, not watts) and/or benefit from AC (mostly motors), there's still an annoying valley of power bricks.
I especially hate the type that's hard-wired to the power plug that blocks 1-2 other outlets due to its bulk and inevitably gets lost during a move or trip to storage and back.