Lizzy seems to be kinder towards Wickham for moving towards Miss King, than with Charlotte for marrying Mr. Collins. I somehow don't like the scene in P&P2, where Wickham 'explains' himself to Lizzy. I don't think Lizzy would be so indelicate or unladylike as to express openly her disappointment that she was no longer his object. It may have been inserted for other reasons, I guess!
Also, she seems sure that Wickham 'defected' towards Miss King not from genuine affection. Where does she have proof for that? Perhaps, Wickham did care for Mary King. And she seems to 'coldly' reason everything out, which proves that she had no real love for him.
What I don't get is, why were Lydia and Kitty so upset about it? Were they concerned for Lizzy(not!), or were they lamenting the general loss of a 'flirtable' officer?
How much did the Meryton rumour mill link Lizzy with Wickham before this? In P&P2, it is generally talked about, but there is no evidence in the book.