An EasterEgger, by most peoples definition, is a bird that has a blue blue-egg history (has Ameraucana or Araucana blood SOMEWERE), that may or may not include the following features - lays blue eggs, has muffs, has a tail, has a pea comb, and has green legs.
Really, EasterEggers are mutts - they are not bred for a specific perfection, like other breeds. Others are bred down to the shape of the bird, the color of the legs, the size of the eyes, the angle of the carriage of the tail and wings, the color eggs it lays, and so many other things. For a one real thing - colored eggs - which they dont always produce anyway. I personally really don't think you can consider a EE to be breed - they are NOT regulated by breeding like others. A EE with parentage, of say a LeghornxAraucana will look MUCH more different then say a FaverollexAmeraucana cross. Their shape will be different, their color will probably be different, the size of their muffs (and shape, too) may be different, their leg color may be different, their egg color could be different - along with so many other things, such as temperment. 
If a EE is a crossed bird, which it is, then it is considered a mutt, crossbred, or etc. I don't think there is anything wrong with that at all - I completely accept the fact, and love my birds none the less.