If the woe is the same woe in all three accounts, then Matthew and Mark's reference to the gospel being preached to all nations is a detail skipped over by Luke, and the surrounding of Jerusalem and its desolation mentioned by Luke is just a different way of saying "the abomination of desolation" used by Matthew and Mark. Even though the Lucan description of this section seems to me to better fit the events of 66-70 AD, the phrase "all that is written will be fulfilled" doesn't really fit well with 70 AD--especially considering it's 2010 and all that is written still hasn't been fulfilled.
The only way to keep the preterist hope alive, therefore, is to see the woe on the pregnant and nursing as referring to two distinct occurrences of such a plight. Otherwise, the language of the end which dictates the interpretation of Matthew and Mark, would carry for Luke's account too. The dual fulfillment of things like the "Abomination of Desolation" (seemingly fulfilled in Antiochus Epiphanes, yet used by Christ to refer to something yet undone) perhaps allow such an approach, but I think it strains credulity, so in the end I must dismiss it, and with it, the preterist interpretation of the Olivet Discourse.