Today at 3:30 p.m. Pacific time Tesla will officially begin first retail sales of its long-anticipated Model S electric sedans with the delivery of about 10 cars following a 30-minute or so ceremony at its Fremont, Calif. factory.

Actually, a few have already been pre-delivered to insiders, but today is the official start that has media and industry watchers saying such things as this vehicle will “make or break” the company, and the ambitious potentially paradigm shifting automaker is contemplating a “moon shot.”

Tesla’s Model S follows production of its first car, the 2008-2011 Roadster coupe which sold over 2,300 units, and this year the company is edging toward mainstream offerings, although yet in upper echelon territory to be sure with prices ranging from $57,400 for the 40-kwh entry level, to over $100,000 for packed 85-kwh iterations.

The first 1,200 S Models to be delivered will be the premium examples with 85-kwh batteries, and following at an undisclosed point in time will come the 60-kwh versions, eventually followed by the 40-kwh versions.

The U.S. Environmental Protection Agency rates the Model S as delivering 89 mpg combined miles per gallon equivalent, with 88 “mpg” for the electric car in the city, and 90 on the highway. Range for the 85-kwh versions – which incidentally the EPA has listed as 83 kwh – is an EPA-rated 265 miles. If driven sedately, Tesla estimates 300 miles range should be attainable, and possibly even as much as 400 miles.

Yesterday, Tesla announced it has entered an agreement with Wells Fargo to provide retail financing assistance for its cars. The usual caveats apply – the actual rate, term and down payment requirements for any loan will be based on each customer’s credit profile and financing is subject to approval.

“Affordable financing for electric vehicles is incredibly important as it provides our customers the ability to combine their monthly payment with monthly operating costs and realize the economic benefits of an electric vehicle from day one,” said Elon Musk, Tesla Motors co-founder, CEO and chief product architect. “Because the cost of electricity is significantly less than the cost of gasoline, the value proposition to customers on a purely economic level is going to be much more compelling than an internal-combustion powered vehicle.”

The company will also be offering demos over the next 45 days in its Get Amped Model S Tour. Expected are as many as 5,000 test drives for Model S reservation holders and friends.

The tour will start in Fremont on June 23 and 24, then will head to Los Angeles the following weekend. It then will travel to targeted cities in the U.S. in July and August, and will include one weekend in Toronto, Canada.

In a phone interview a couple hours before the ceremony today, Tesla Communications Manager Shanna Hendriks said the company was not prepared to divulge an exact production schedule in the days and weeks ahead, but would “slowly ramp up production focusing on quality” while striving to deliver on schedule.

As mentioned, eyes are on the maverick company as it boldly embarks on meeting the expectations of a sizable number of fans and well-wishers hoping to see the company change the American automotive landscape in due time.

The company’s stock has continued to climb this week, today is balancing between $32.46 and $33.98, and some have speculated in coming weeks it could break to record highs on positive news.

Of course even more positive news will have to wait until an even later date when the company shows next year it can sell over 8,000 units per year, which Musk has said is needed to get back in the black.

Reports are that Tesla has lost over $750 million since its 2003 founding and the Model S – its first mass-market car, albeit still a niche product – is a high-stakes gambit that cannot afford to fail even as Tesla hopes to later market its Model X crossover and down-market cars yet to be revealed.

Tesla says it will deliver about 5,000 Model S cars this year as it works to whittle down its waiting list in excess of 10,000 reservations holders.

Naturally, also, the company continues to take reservations online and at 14 Tesla retail stores around the U.S. and elsewhere in the world.

Production of left-hand drive European-market cars is slated for the fourth quarter of 2012 with deliveries beginning in the first quarter of 2013, Hendriks said.

Right-hand drive versions are intended to begin production in mid-2013 for European and Asian countries in which that configuration is sold.