It's been over 105 days since Apple has opened a new Apple Store, beating the previous record for longest gap between openings. The old record was set in 2003, and that gap extended between January and May. This gap began in November and will continue until we get a new store. ifoAppleStore has a great infographic that will help contextualize the break for you.
It could be tempting to say this hints at some kind of slow down in sales, but that conclusion can't be confirmed without a whole lot more contextual data. Since most of the Apple Stores open just before Thanksgiving, with a few more coming in around Christmas time, this is the time of year when we'd expect to see a slowdown anyway. The gap could just indicate that Apple did a great job of getting all their stores open in time for Christmas 2010. Let's see how things shape up in the last half of 2011 before we start to wonder about new Apple Stores.