The resident creationists' other arguments have been successfully dealt with; one gets suspicious when the professional creationists themselves backtrack on such arguments.
But the faint young sun is, however, a real one, and mainstream paleoclimatologists have long recognized its reality. Beyond more than a billion years or so ago, the Earth would be too cold to have liquid water -- and a billion years is MUCH greater than 6000 years, meaning no support for YEC.
However, they have come up with some plausible solutions that involve changes in the composition of the Earth's atmosphere. There are various gases that have infrared absorption bands that can make them act as greenhouse gases; three likely ones for the early Earth are water vapor, carbon dioxide, and methane. So if the Earth had had more CO2 a few billion years ago, it would be warm enough to have liquid water.
In fact, there appears to be a "geochemical thermostat". If the Earth becomes too cold, then rocks do not weather as much, and less CO2 becomes consumed by their weathering. Allowing CO2 to accumulate and heat the Earth. And if the Earth becomes too warm, then rocks weather faster, consuming more CO2, and thus cooling the Earth. Here are some links on that question:
http://earth.usc.edu/~geol150/variability/co2.htmlhttp://www.geosc.psu.edu/~kkeller/lecture3.pdfhttp://www.soc.soton.ac.uk/...rses/oa413/notes/Lecture14.pdfhttp://geowww.gcn.ou.edu/~msoreg/tes/Early%20Atmosphere.htm
Carleton College: File Not Foundhttp://members.cox.net/jmadams2/Feedbacks.html
I got these links off off Google by searching for
"carbon dioxide" water weathering rocks "faint young sun" temperature
™ Version 4.2