Scratch

you've just put the exact same thing
But i'm assuming you mean this:
<key pressed?>
where it reports the key pressed, and undefined if no key is pressed.

I would support, except for the fact that you can make a new block in 2.0 in which it makes that block using a bunch of ifs and ors, but you would have to first make a boolean (key pressed?) block.

I believe being able to use reporter blocks in the "key pressed" blocks, would be a better choice, if you wanted to be able to map keys:

when gf clicked
set [key v] to [space]
forever
  if <key (key) pressed?>
    say [do stuff]
  end
end

You could then use the ask block to define that key, though I understand that might look a bit ugly and clash with the look of your project. A "key currently pressed" block, as you describe, would be great if pulled off well (what happens if I'm pressing two keys? I think it should return the last pressed one).