A better solution is length-encoded lists (often called Vectors):

  data Vector length a where
    Empty :: Vector 0 a
    Cons :: a -> Vector n a -> Vector (1 + n) a

But Haskell isn't very good at such encodings. Type-level computation is often not worth it.

That said, even NonEmptyList is sometimes useful. For example, some Prelude functions could use it:

  group :: [a] -> [NonEmptyList a]

Making common idioms like:

  map head . group ...

Safe again.

Not sure what you mean by:

> How could you get the last element from your NonEmptyList? How could you tell how many elements in it?) Exactly two.

  import Data.Monoid
  import Data.Maybe

  lastNel :: NonEmptyList a -> a
  lastNel (NEL x xs) = fromMaybe x . getLast $ mconcat $ map (Last . Just) xs

  lengthNel :: NonEmptyList a -> Int
  lengthNel (NEL x xs) = 1 + length xs