iPhone 7 Plus and all Jet Black iPhones 7 already sold out, so don't bother lining up for those.
Apple has issued a statement to several media outlets, including TechCrunch, on the extremely limited availability of iPhone 7 Plus, and of Jet Black in all models, at launch this Friday:
We couldn't be happier with the initial response to iPhone 7 and iPhone 7 Plus, and we are looking forward to beginning sales through our retail stores and partners around the world.
Beginning Friday, limited quantities of iPhone 7 in silver, gold, rose gold, and black will be available for walk-in customers at Apple retail stores. During the online pre-order period, initial quantities of iPhone 7 Plus in all finishes and iPhone 7 in jet black sold out and will not be available for walk-in customers. Availability at partner locations for all finishes may vary and we recommend checking directly with them.
Customers can continue to order all models in all colors on apple.com. We sincerely appreciate our customers' patience as we work hard to get the new iPhone into the hands of everyone who wants one as quickly as possible.
That's a stark contrast to previous years where it always seemed like Apple held some stock back from the pre-orders to ensure availability at retail. It does follow a pattern, however, of Apple de-emphasizing in-store launch in favor of the online pre-orders.
The huge lineups were great publicity for Apple and demonstrable signs of the popularity of iPhone, but they weren't a great experience for customers who had to get in line days early at times, or risk sellouts and settle for a model that wasn't exactly what they'd wanted.
Carriers and big boxes may or may not have any iPhones 7 Plus or any iPhones 7 in Jet Black, but it doesn't seem likely, and even if they do, they'll probably be extremely scarce.
Either way, if you want Jet Black or an iPhone 7 Plus for certain, you'll need to order online ASAP to get in the queue. If you want an iPhone 7 in silver, gold, rose gold, or matte black, you can still try and line up super early, or likewise order online ASAP.