Sean Kovacs, the person who wrote Google Voice Mobile, has re-submitted his App for Apple approval as GV Mobile +. He said that he had to jump through some "extra hoops." The App will cost $2.99, the same price it's always been.
He says it should be about a week or two before it hits the US App Store. Many may remember about a year ago when GV Mobile was pulled from the App Store.
It was said that "Apple believed the application duplicated the core dialer function of the iPhone," it disappeared for a while, but it was still possible to get the App through Cydia on a jailbroken phone.
The update comes with some improvements, such as new graphics for the keypad, internal favorites, copy/paste into keyboard.
Here's a history of the whole mess: Link.
The developer has more info on his blog: Here