I did alot of research on listeriosis during my 3rd pregnancy. My doc told me not to worry about it but it seemed as though ALOT of moms on various online boards were stressed about it. So I went to a local med school library and looked through medical journals and books and stuff in addition to online research. Know what? Don't worry about it!
Yes, IF you get it while pregnant it could result in a miscarry (most people just get sick with flu-like symptoms). HOWEVER, please look at the odds/chances and then make a decision based on what you are comfortable about. We take risks every single day. Of course, the most dangerous thing to do while pregnant is driving or riding in a car -- and yet pregnant people do it all the time. Or crossing a street. It boggles my mind that so many people are worried about something so remote as listeriosis but still get in a car. If you ride in a car just once during pregnancy you have a MUCH higher chance of hurting your unborn baby than if you ate cold cuts and hot dogs everyday for 9 months! Anyways... the odds are like 1 in 30 million of getting listeriosis... but only 1% of those who actually get it end up with serious problems, including miscarriage. In other words, you are much more likely to get hit by lightening, a few times, than hurting your baby by eating lunch meat.
In my opinion (and those of my doctors), there's enough stuff to stress about when pregnant... know the facts and then pick and choose what is really worth stressing about.
But one more thing... it's not just from hot dogs, lunch meat and soft cheeses... confirmed cases of listeriosis have come from eggs, shrimp, even pasteruized milk, among many other foods. So if you are avoiding lunch meat (and cold cuts aren't cold cuts if you have to eat them hot - yuck!) it doesn't make sense unless you avoid all other known sources, too.