It's a cultural thing I suppose, but I would continue to tip. Contrary to what many people seem to think, it's not just carrying my food from one place to another. That's a big part of it, but they have to do so in a timely manner, they have to remember what I ordered (whether they write it down or not is up to them), they have to be personable and they often have to clean up after me. More than that, they have to be on call should I need anything, be prepared to deal with my bad attitude should I have one (I don't usually, but there are definitely people out there that do), and anything else that may come up. And if their shift is up while I'm still eating they have to stay longer and wait for me to get done, even if that takes me an extra hour.
So, in light of that, I would still tip them. I might tip them less, but I tend to tip fairly well in any case so it would likely end up fairly normalized. If they did poorly I'd tip them just as poorly as I do now. Have some stories from there I could tell you...