No
The Space Shuttle, so far, has killed fourteen people, merely trying to attain an orbit about two hundred fifty miles above the Earth. How is it then, that a third of a century ago, with less computing power in the entire rocket than in a present day twenty dollar Wal-Mart watch, NASA claims to have gone 100,000% farther, six different times between 1969 and 1972, landing on another celestial body and then returning, without ever killing anyone?
I already covered this, comparing the Shuttle and Apollo are like comparing Apples with screwdrivers. Apart from going into space, they are as totally different as is possible, and the Shuttle managed to complete 50 missions without any deaths, Apollo only had 15 the flew, even if you include Spacelab and the Soyuz missions, 16 in total, one of which had fatalies on the ground, and one nearly cost the lives of the crew, and shortened the programme.
How could they have powered air conditioning in two hundred fifty degree heat for three days with batteries?
Answered already for the suits, but perhaps we need to do the LM too. First, the temperature wasn't 250°F (it gets to a maximum of about 243°F or 117°C) while the crew was there, so that temperature is irrelevent to the missions.
Secondly there is no air, so the temperatures that were reached where the ground temperatures, not an air temperature. Even on earth, the ground temperature can be a lot hotter than the air temperature. Next time you have a hot sunny day, check the temperature of a rock that has been sitting in the sun, you'll find that it can quite a bit hotter then the surrounding air but doesn't pose a threat to your standing there.
Thirdly. The LM was designed with this in mind. The legs kept the LM body high off the surface, and it was covered in reflective layers to keep as much of the heat from being radiated to it as was possible (in most areas, some parts actually were designed to absorb the heat so they could keep the parts there are a higher temperature) The LM was landed with the crew windows pointing down sun to avoid the sun being directly in through the windows and they had muliple layering as well.
Fourthly, whenever the crew weren't inside the LM, there was no atmosphere in the LM, they would decompress the craft to leave, and not recompress it until they were ready to remove their suits.
and Finally, there were several heat exchangers that worked the same way as the PLSS subliminator to extract waste heat from the LM, something that caused a problem on Apollo 13 after they shut off the electronics and blocked out the sun. Because these systems were designed to counter the heat produced by these things, without that heat being produced, the interior of the LM cooled down too much and resulted in the craft being very cold.
Why is the "second round" of "returning" to the moon estimated to be no earlier than half a century after the first?
Politics. Politics and money. There has never been a political reason to return. Apollo got canned after Apollo 13 because the politicains decided it was a) a waste of taxpayer money which they could be spending on their own waste of money projects, b) it was a "democrat" program and the Government was Republican and the then President had his own space programme in mind, the Space Shuttle, c) after the near fatality of Apollo 13, it was considered too dangerous and no politician wanted dead astronauts in space on their re-election campaign.
Since then only two Presidents have been willing to fund a return. Reagan in the 80's and now Bush Jr. Reagan floated the idea and a lot of options were considered, including if it was possible to refit the Shuttles for such a mission (it is, but it's not practiacable, you'd have to almost redesign the entire thing, so might as well just build a purpose built ship for the job.) In the end it was scrapped because it would cost too much. Now with the shuttles retiring, NASA needs a new ship anyway, so designing and building one that can get to the moon as well as servicing the ISS is a practical idea. It doesn't actually cost a great deal more to get to the moon once you are in Earth Orbit. Because of the need for the new ships, and the opportunity to return, it will hopefully happen (the next administration could still pull the plug on the moon missions even though they'll have a ship capable of doing it) but there is little point in rushing this time as it's not a race to get there any more.
Just on a time scale. Apollo was started in 1958 and landed in 1969, 11 years. Constellation was floated in 2004 and is scheduled to land in 2020 (though originally planned for 2016-2018), 16 years. It doesn't have the Apollo budgets, it is being planned as an ongoing mission to build a base and have long term stays on the moons (more then the entire ten days of Apollo flight.) The craft are to be re-useable and it includes the programmes for retraining the astronauts to fly a new craft (Mercury, Gemini and Apollo were all similar.) Considering those factors with the slower pace, 5 years isn't that much.