How does Pip's relationship with Estella change?

Great Expectations is a bildungsroman detailing the growth of its hero, Pip, from childhood to adulthood. His name gives some indication of the role he will play in the novel: beginning as a "pip" that will grow into something greater than its origins. As Pip changes, so does his relationship with Estella, Miss Havisham's beautiful ward.
Names are important in this novel. "Estella" as a name accurately represents how Pip sees the girl herself: beautiful, distant, and unattainable, like a star. At first, when they are children, Pip is overawed by Estella, and he pursues her even though she treats him badly. Having been brought up by the scorned bride Miss Havisham, Estella is emotionally stunted and unable to love Pip as he loves her, but despite Estella's protestations, Pip views attaining Estella as representative of his wider goals in terms of class aspirations. When they first meet, Pip is only a blacksmith's boy. He believes fruitlessly that, when he meets her again as an adult who has come into money, she may see him differently, but this does not happen. However, Estella is very honest with Pip, saying that she is pursuing the rich Drummle only for his money and "deceives and entraps . . . all of them but you [Pip]." Only with Pip is she honest about herself.
At the end of the novel, after some years, Pip and Estella meet again, and Pip's attitude towards her has changed. Dickens actually wrote two endings to the novel. In the first ending, Estella is portrayed as having learned from the sufferings of her abusive marriage to Drummle; it has "given her a heart to understand what my heart used to be." But her meeting with Pip is brief, and it is clear that Pip has moved beyond his passion for her.
In the second ending, there is a greater sense of closure between Pip and Estella when they meet again at Miss Havisham's house. Pip declares that they are "friends," to which Estella says they "will continue friends apart." Despite this, however, Pip says he "saw no shadow of another parting from her," which leaves the audience to wonder whether Pip is still fruitlessly longing for Estella, who will only ever be a friend to him, or if they will finally be together.