Shocking what happens to the mindset of a people when you combine dwelling on the persecution of your ancestors and 'chosen ones' rhetoric.
It's a despicable attitude, to be sure. It doesn't bode well for peace when neither side really recognizes the rights of the other...
I would say the act of sitting down and negotiating is evidence enough of a willingness to negotiate. Asking to negotiate as much so as actually doing it, regardless of the demands of the other side. If it weren't the charter issue (and it's not like this charter is registered by a local notary public or something), Israel would demand they not ask for right or return. Or dismantlement of settlements.
It seems like whenever it comes time to negotiate, Israel insists that the negotiation be done and entirely in their favour before it even starts. Not that Hamas and Fatah haven't done the same, but Hamas and the PLO united on negotiating based on the 67 borders is already a HUGE shift towards reasonable terms and Israel won't even negotiate with Fatah anymore because of the unity government, which is a huge step back from the table on their side.
I agree, and israel hasn't had a fair negotiation since olmert (can we blame arafat for that one?) but I'm not trying to determine who's right and wrong in the negotiations. So hamas shouldn't change the charter because israel has been a bunch of cocks? They don't even have to do it, they simply have to promise to do it, but their excuse is that it can't be changed for 'internal reasons'. Without more explanation I call bullshit; it's being used for hardline political reasons, just as what happens with likud. It's despicable on both sides.
EDIT: to elaborate, think about it this way. You're sitting down to negotiate with someone who has done some shitty things to you and you've done some shitty things to them. Palestine wants control over it's borders and and end to the blockade, fine. But the negotiation hinges on a basic promise. Palestine, even thought it now has access to weapons through more open borders, is promising not to continue attacking israel (and israel of course promises not to attack the new Palestinian state). But there's this document, that the Palestinians have complete control over, that says their stated purpose is the destruction of the state of Israel. So Hamas is saying: "we totally won't attack you, we're cool now, don't worry about it, just ignore that document over there that says otherwise." Assuming agreement is reached on all other issues, this one still remains, however small it is. It's super easy to fix, yet everyone refuses. Why? It's seems like the lowest cost thing to give up as a first concession to get people to the table.