Few events in the technology world can rival the attention a new iPhone launch draws, but the return of Steve Jobs to Apple Inc would surely be one of them.

The new, souped-up iPhone 3GS goes on sale this Friday, as investors and gadget lovers alike await the presumed re-emergence of Apple's chief executive, who has been on medical leave for about six months.

The consumer electronics giant remains mum on exactly when and how Jobs will come back, repeating the now-familiar mantra that Apple looks forward to his return at the end of June.

It is possible, analysts say, that Jobs could soon shift to a new role to focus on big-picture issues and products, while Chief Operating Officer Tim Cook manages the day to day.

At the very beginning, it will be him coming back as CEO. If they do make a transition, it will be a slower, methodical type of transition, said Pacific Crest Securities analyst Andy Hargreaves.

With Apple's shares already up 60 percent this year, few analysts expect Jobs' return to have a lasting impact on the stock beyond a short-term bounce. If Jobs reduces his role, analysts say a stock dip is also likely to be short-term as Wall Street has become more comfortable with other executives.

People feel good not just about Tim Cook but about the depth of the team in general, Hargreaves said. They have done a good job of trying to highlight some of the other people that are there.

Jobs, a pancreatic cancer survivor, stepped away from day-to-day duties in January, citing unspecified health issues. In his absence, Cook has overseen operations, although Apple said Jobs remains deeply involved in decision-making.

Analysts expect Jobs' return to be an understated affair at Apple. We expect it to be very smooth, said Kaufman Bros analyst Shaw Wu. We don't expect anything that different from his departure on medical leave, which was announced in a personal message to company employees.

IPHONE LAUNCH

An example of how Apple continues to upgrade its product line even with Jobs on the sidelines is the new iPhone 3GS, which features a faster processor, video capability, an improved camera and better battery life.

The phone -- in the works before Jobs stepped away -- will compete with Research in Motion Ltd's BlackBerry and Palm Inc's Pre, which has seen strong early demand.

The 3GS goes on sale on Friday in the United States and seven other countries. Past iPhone launches have seen a circus-like atmosphere with some people camping out overnight, but crowds were scarce on the eve of this launch.

At Apple's flagship New York store in midtown Manhattan on Thursday afternoon, only three college students were lining up in the rain. It's more evolutionary than revolutionary, said Matt Dodd, 18, echoing the words of at least one reviewer.

Dodd said he was not buying the 3GS himself but saving a spot in line for his friend who has the first generation iPhone. But for the kid who's getting it, it's a big deal -- he's going from 2G to 3G.

The new phone has won positive reviews from the likes of Walt Mossberg at the Wall Street Journal and David Pogue at the New York Times. But some have also noted that the device is not a huge technological leap over the current iPhone.

And given that many people have already preordered the device, analysts said the first-day crush could be lighter than in years past.

From a hardware perspective, it's nothing earth-shattering, but from a user experience, it's going to be far superior to the current 3G because it's much faster, said Broadpoint Amtech analyst Brian Marshall.

He expects Apple to sell some 5 million iPhones in the June quarter, up 32 percent from the previous period, and said exclusive carrier AT&T Inc could see 1 million activations of the 3GS by the end of the month.

Apple shares closed up 0.2 percent at $135.88 at the end of regular trading on Nasdaq on Thursday.

(Reporting by Gabriel Madway, additional reporting by Franklin Paul, editing by Tiffany Wu, Lisa Von Ahn, Tim Dobbyn)