They still haven't lost consecutive games this season. Based on that, I think that it can last the rest of the season. Well, by "it," I don't mean 1st in the NHL, which they probably won't keep, but near the top (say, in the top 6) is entirely possible. It's really hard to imagine a team with this much consistency totally going off of the rails and plummeting in the standings.
The real question is whether it'll carry over into the playoffs, when everything changes. Sometimes, the hottest, most consistent teams during the regular season stumble when the playoffs start (ex. Canucks and Blues in recent years).
BTW, it's not just on the backs of Weber, Rinne and Forsberg/Ribeiro/Neal. They're leading the team, but many others have picked up their games. Guys like Wilson, Josi and Ellis are having career years and the team wouldn't be quite as good as it is without it. Star players can put teams on their backs for a month, but it takes contributions throughout the lineup to stay so hot and consistent through half of a season.