Jeff, you can do WW online. Still, I would recommend going to meetings. There's something that really helps, at least for me, about the tacit (even semi-imaginary) accountability you have to the group and the leader, and the weekly weigh-ins and encouragement you get when things are going well. My goal is always to lose at least SOMETHING by the next weigh-in -- even half a pound -- rather than trying to lose 25 pounds by sometime in the distant future. I suppose it's a little like the AA "one day at a time" -- it's helpful to break a goal into manageable steps.
I have a couple of concerns about meetings. For one thing, getting to them might be an issue for me, if attending a meeting would require a long or complicated trip on public transportation. Then, too, it seems my days are already too short, and most evenings once I get home I'm too tired to do much of anything. It's daunting to think about shoe-horning a WW meeting into days that are already not long enough. "Something" would have to "give," to make room for a WW meeing, and that "something" could well have to be something else valuable, like going to the gym. I'll admit, too, that I would not be comfortable if I turned out to be the only guy there--which would have been the case when they held WW here where I work. So being able to do it on line, at home, at my own convenience, certainly has its attractions--which is not meant in any way to disparage the good reasons you suggest for attending meetings.
As for whether to wait until after the holidays, I would strongly recommend starting now, for several reasons. 1) It will limit the amount of weight you gain over the holidays, so you don't wind up with yet another 5 pounds to lose afterward. 2) It will keep you from slipping into that mentality of, "Oh well, I'm going to start Weight Watchers in January, so I might as well eat everything I want while I still can!" 3) It's not like you necessarily have to pig out every single day between now and New Year's -- WW lets you keep track of your food on the days when there are no festivities going on, but also gives you extra points to use on the days when you're at a party or dinner or whatever.
Of course, I already try to be careful about my eating now. But from Halloween through New Year's there are so many parties, and most of them I really can't get out of: I have three coworkers with birthdays between now and the end of the year (plus one has her 10-year anniversary of her employment); fortunately, we polished off those occasions for celebrating with one team luncheon today.
But then between Thanksgving and Christmas here at work there is the department holiday party, then the company-wide holiday party, then my team is having its own "goodie day," and people are always bringing unscheduled "treats" into the office, and then outside of work my leather club has its holiday party, and my medieval reenactment group has its annual Yule revel early in December, and friends want to get together to share a meal, and--oh, yes--there are the actual holiday dinners with the kinfolk. It's just too much!
And my supervisor is already planning a lunch to celebrate my 10-year anniversary just after New Years!
The idea of puttiing off trying WW till after the holidays is also somewhat based on my own history. For several years, after the holidays and into the early months of the new year, and including Lent,
I have managed to discipline myself and lose about five pounds. The trouble is that I can never seem to lose more than five pounds, and it all comes back when I do any traveling and can't maintain the fairly strict eating habits I ordinarily follow at home. (I gained another five pounds on my recent ramble to Boston and Provincetown, but I've managed to lose about three of those pounds since I've been home.)
Without knowing more about the WW program, my actual goal initially would be very modest, to lose ten pounds and get my BMI back out of the overweight range; fifteen pounds would be even better, but I'll settle for losing ten and keeping it off. But based on what I have been able to do over the past few years in the months after the holidays, I feel I have a better chance of meeting my goal if I wait until then, rather than try to start now.