In just a few hours’ time, Steve Jobs will be unveiling the new MacBook Air at the Back to Mac event. Meanwhile, we can whet our appetites with these rumors from Cult of Mac, who discovered that the new incarnation of the MacBook Air will pack up to 10 hours of battery life. The MacBook Air is rumored to come in two sizes – one with a 13.3″ display and a netbook-type one with a 11.6″ display. And according to early testers, it has a fast boot time, a boxy design similar to the iPhone 4, and an aluminum unibody lighter than 3 lbs. You can also expect it to have 2 USB ports, an SD card slot, a mini DisplayPort adapter, and 2GB or 4GB RAM (which you can upgrade with the SSD). Price-wise, the 13″ model is said to be priced at $1,000, while the 11″ one will sell for $999. Guess we’ll soon find out if these rumors come anywhere close to the actual specs and prices.