Tomorrow we’ll be hitting up the Macworld Conference & Expo in San Francisco for Steve Job’s highly anticipated keynote. Rumors are rampant that Apple will be unveiling an ultraportable notebook that will break the mold. One analyst, Gene Munster at Piper Jaffray, told USA Today that the laptop will be half as thin as existing Mac laptops. But we expect a lot more out of this system than an iPod nano-like profile. According to 9to5Mac, among several other sites, the new notebook may be dubbed MacBook Air, which would be fitting for two key reasons. Some are saying that Air is a perfect fit because of the laptop’s supposed featherlight weight and because it may have built-in mobile broadband, either in the form of 3G cellular or maybe even Mobile WiMAX. We have no idea what to expect, but it’s certainly true that Apple could really use an ultraportable to round out its lineup.And we have no doubt that it will be one of the sexiest machines yet, one that will likely sport an LED-backlit display and solid state hard drive. These two components will not only save on weight but also allow the new Macbook to run longer on a charge. Although SSDs are still fairly expensive and relatively low in capacity, we think the Mac faithful will be more than happy to make those trade-offs to own what could be the hottest notebook on the planet. We’re more interested in how this ultraportable might change the way we compute. Will it have touch capabilities and support gestures like the iPhone? And will it have inking capability for taking notes? Dell has already fired the first shot in a sense with its Latitude XT Tablet, the first convertible on the market with a capacitive screen. And while the $2,499 starting price of that system has been criticized, something tells me that should this new MacBook support touch, it will justify the premium by doing more with the technology. So what else might Steve Jobs have up his sleeve? Most industry watchers are saying that Apple will finally roll out movie rentals for $3.99 a pop, which will make the iPod and iPhone a more viable video platform. We also hope that consumers will be able to order flicks directly from the Apple TV, which for now required you to order shows and movies online and then sync them over iTunes. As for the iPhone, we don’t expect a 3G model to be announced (although anything is possible) but we do expect to see some of the first third-party apps demonstrated, whether it’s on stage or behdind the scenes. One mobile application developer we spoke with at CES told us to expect at least an update on this front at Macworld, despite the fact that the iPhone SDK technically won’t be made available until next month. We’ll have complete analysis of all of the Macworld announcements tomorrow and hopefully some hands-on time with the rumored Mac ultraportable. Stay tuned.