According to Mac blogger - and occasional Macworld contributor - John Gruber, Apple will unveil the iPhone 3GS later today at the Worldwide Developers Conference (WWDC) in San Francisco.

Gruber, who has a track record of correctly predicting new Apple products, says he has heard that the phone’s official codename is iPhone 3GS.

"I’m not certain that’s what it’ll be officially named, but my hunch is yes. I have no idea what the S stands for," Gruber said on his influential Daring Fireball blog, adding "1.Speed?" in a footnote.

Gruber's other predictions are in-line with various rumours and titbits currently circulating Web sites, blogs and forums.

"I expect Apple to announce updated iPhones with significantly faster processors, twice the RAM, and twice the storage. I expected prices to remain the same as the current line-up: $199/299 for 16/32 GB, respectively. The video camera is going to be a major selling point," said Gruber. He also believes that battery life will be 15-20 percent longer than the current iPhone 3G.

Gruber adds that stories of significant iPhone price cuts, down to as little as $99, are also likely to be true, this may become the entry level price for the existing iPhone 3G model. The Financial Times, citing anonymous sources “familiar with the initiative”, reported it as fact.

Macworld WWDC 2009 stories

Live update: WWDC 2009 keynote

WWDC: New iPhone to be named iPhone 3GS?

Mac hardware figures to be MIA at WWDC

Aussie MacTalk asked to take down "end of life" iPhone rumour

Check out our new Macworld Mobile site.

Follow Macworld UK on twitter: