Despite the mounting number of violations of the "cease fire," all indications are that Hamas is really trying to adhere to its terms. This is evidenced not only in Hamas statements made in Arabic but also in their actions.
Hamas has gone on a spree of arresting members of the Al-Aqsa Brigades, which perhaps is nothing new, but their latest arrest is noteworthy: they abducted Abu Qusay, the Fatah spokesman who on Thursday and Friday criticized Hamas for the truce.
While Hamas has acted in duplicitous ways in the past, they have always been comparatively far more honest than their Fatah counterparts. Even in the "truce" of late 2006, Hamas could argue that they had never formally accepted a truce nor had they agreed to enforce one among other groups.
Obviously Hamas continues to smuggle explosives and weapons into Gaza in opposition to the Israeli understanding of the "calming" (Hamas never publicly accepted that position, as far as I can tell.) And it is entirely possible that Hamas considers this truce minimally binding because they made these promises to fellow Muslims in Egypt and not to the Jews directly. It does, however, bring up an interesting question:
What should a state that cares about democracy and human rights do when its most credible negotiating partner has zero concern for democracy or human rights? What is the moral course to take when the conditions of the agreement involve the partner acting immorally?
For better or for worse, both ancient and modern Israel is situated in a really bad neighborhood, and it has enough of a hard time existing in relative security without adding concerns about how the neighbors act towards themselves. On the other hand, any ultimate peace - if it is remotely possible - will be based on all the actors in the region accepting basic human rights for everyone else, and any short-term solutions might endanger the longer-term ones.
I don't have a good answer.