This is an interesting topic. I would imagine there are those who would prefer no smoking of any kind, and those on the opposite side who say a long as it doesn't harm anyone else, it should be okay. To be honest, I think a smoker could abstain for a couple hours at a restaurant , if for no other reason than to avoid making someone else uncomfortable. I did run across an article on CNN that shared some points on the subject of e-cigarettes. After reading, please take a second to answer a yes no poll question asking, " should e-cigarettes be banned in restaurants." at the bottom of this post.

E-cigarettes don’t stink
You won’t smell the e-cig of the person at the next table because these battery-powered devices emit vapor - like the stuff that comes out of your mouth when you breathe. No one’s palate will be wrecked by sitting near an e-smoker, as far as I can tell.

E-cigarettes are kinda green in theory
There are no butts to toss on the ground and no air pollution created., though, admittedly, a smoker may eventually need to dispose of the battery.

E-cigarettes are tacky and dorky
Many critics single out the fact that e-cigs are simply plastic sticks. Some of these gizmos sport fake burning ends, too. As Eric Ripert said: “It's weird to see someone smoking with a plastic cigarette.”

E-cigarettes have nicotine but none of the other harmful ingredients of normal cigs
CNN Health explains what’s in these products and discusses their safety. The verdict: More research is required because no one knows if there is a long-term impact on smokers or on the environment.

The law is murky
It’s not clear if Bloomberg or the next mayor (or politician) will attempt to ban e-cigs too. What is known is that e-cigarettes are clearly exempted from existing smoking bans in some cases. See the website for Americans for Nonsmokers' Rights for state- and town-specific rules and regulations.

E-cigarettes may keep smokers from leaving the table and smoking outside
Chefs don’t like it when the food arrives at the table on time but the patrons are outside smoking. Dishes get cold or else they come back to the kitchen and get stuck under a heat lamp taking up space. And many New Yorkers can’t stand it when smoke rises up into windows as small crowds of (drunk and rowdy) smokers band together outside to satisfy their urges in between bites and sips. Keep smokers inside and these annoyances would be kept to a minimum.