Engadget - And just like that, HP joined the Ultrabook party. After announcing the Folio in Australia yesterday, the company went and made it official here in the states too. And man, do we get the feeling the outfit's been watching the competition very closely: this guy starts at $900 and comes standard with a 128GB mSATA SSD and a backlit keyboard. Provided it comes close to matching its promise of nine hours of battery life, it could give the identically priced Toshiba Portege Z830 a run for its money. Not to mention, it undercuts the MacBook Air ($1,299 and up), along with the ASUS Zenbook UX31 and Lenovo IdeaPad U300s, both of which start at $1,100 with a 128GB SSD and no backlit keyboard. Good on ya, HP.