Apple CEO Tim Cook may find it hard to wow tech fans at his long awaited event tomorrow (10:00 AM PT) considering  how much they already know — or at least seem to know — about the expected unveiling of the iPhone 5. Our sister site, BGR, reports that the phone likely will be slightly thinner and taller than previous models. It will have a four-inch display (up from 3.5 inches), access to 4G LTE networks, 1 Gb of RAM, a more powerful processor, and a new proprietary mini dock connector. Others also expect to see Apple ditch Google Maps and load its own map feature with turn-by-turn navigation, and built-in apps for Facebook and Yelp. Apple likely will promote the entertainment capabilities of the device. The larger screen should continue to have 326 pixels per inch, bringing it to 1,136 by 640 from 960 by 640 pixels. That could “revive the market for on-demand mobile TV and video,” says Ian Fogg, who’s senior principal analyst for mobile at IHS.

Will the new iPhone be a hit? J.P. Morgan’s Michael Feroli stunned even Apple enthusiasts this week when he said that around 8 million iPhone 5s will be sold in the US in Q4. That might contribute $3.2B to the gross domestic product — or, put another way, it “could potentially add between 1/4 to 1/2%-point to fourth quarter annualized GDP growth.” But NPD Group Director of Industry Analysis Stephen Baker warns not to expect a repeat of last year’s sales book after the release of the iPhone 4s. That device appealed to “the remaining huge untapped base of potential subscribers at Verizon and Sprint who were not available to [Apple] previously” when AT&T had dibs on iPhone users. Although the iPhone 5 will be successful, he says that “the inevitability of easy market share gains in the U.S. is not quite so apparent this time around, as it has been in the past.” Apple shares are up 74% over the last 12 months, closing Tuesday at $660.59.