Something that is definitely desirable is... when you respec, some button to display your last spec path!!! (ghost, sort of)
Too many times do i respec just to end up forgetting this or that... and having to redo the whole thing!
Also, it would be WAY easier for me if i could respec only few points! Because most of the time, when i respec, it's just to change a maximum of 5 nodes...