Nearly every major manufacturer has released a 27.5+ FS or 27.5+ HT, some have both, all have 3.0" tires. All the tire manufacturers are coming out with multiple 3.0" plus tire options. I don't believe for a second it's a fad, it's what many riders have been asking for. I know of countless posts on MTBR about how wide of a tire will fit someone's 29er frame, along with lists of actual tire widths, all those people want wider tires. For once the bike manufacturers are listening to their customers. Unlike many other new features, they didn't just make up 3.0" tires, wider tires have a real benefits. When I go to the bike demo rides, most riders want to ride the plus tire bikes first, and I've not heard a single rider say they thought 3.0" tires are not worthwhile.
Manufacturers are scrambling to get plus bike options into the market, a few of of them are rushing to market and getting it wrong. For example, the new Trek Fuel EX Plus bike lost about an inch in bottom bracket height and those early buyers are not too happy about not having enough clearance. They get it wrong because all they are doing is widening the frame by 0.25" to fit the bigger tire and not compensating for the smaller overall diameter of a 27.5+ tire.
As rims, hubs, and tires become lighter and more efficient, there is becoming less of a weight penalty for having plus size tires. I believe you'll start seeing even the sponsored riders running plus sized tires at races. I know I'm faster on plus tires on the trails I ride, so is SportingGoods. We've both timed are average speeds around trails we ride all the time, we are both convinced ther benefits more than make up for the weight penalty.
Not everyone will like 3.0" tires, some guys still love their 26" wheels but the market has left them behind for 29" and 27.5" wheel sizes. I predict the market will continue moving toward bigger tires and plus sizes will get more popular. Not because it's a fad, but because it's what riders are asking for.
