Palestinian and Egyptian 'brokers' are apparently asking Israel for a 'prisoner' exchange, rather than demanding that the kidnapped Israeli soldier be returned by Palestinian militants. In so doing they are endorsing the kidnappers' activities, and in short, saying it is relevant to use kidnapping as a bargaining chip.
The fact that captured Israeli soldier Gilad Shali isn't a bona fidé prisoner, has not been arrested by Palestinian authorities, or charged by Palestinian officials of any crime seems to have escaped their attention. They are, in effect, placing themselves alongside the kidnappers by their demands.
What they should be doing is applying pressure on the kidnappers to release their illegally captured prisoner. If not, they play into the hands of the Israelis, who are making it clear that they will move heaven and earth to retrieve one of their own, which will serve to embolden all Israeli soldiers, and may be part of the intention as they press into Gaza.
As long as these 'brokers' continue to play this game, they are helping break down any chance of a settlement in this dispute.