Thanks for the links. I'll add one link, direct to the project page, since it has links to the actual data, as well as much more detail than is in the articles:
http://berkeleyearth.org/
I note two things on a first read-through:
(1) The project confirmed the data on temperature trends, but the error bar sizes are only reasonable back to about 1860; further back than that, the error bars get quite large. This is glossed over in the statements of findings: for example, the summary of findings (http://berkeleyearth.org/summary-of-findings) says: "Global land temperatures have increased by 1.5 degrees C over the past 250 years", but the error bars in 1750 are about +/- 1.5 C. You can't conclude anything reliably when the error bars are as large as the signal you think you see in the data.
(I also note, btw, that this conclusion is mis-stated in the NYT op-ed by Muller: it says "Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years". Neither of those statements are consistent with the summary of findings page on the project site, which claims, and shows, 1.5 C rise over the past 250 years, as above, and less than 1 C rise over the past 50 years.)
(2) The project looked at statistics on temperature trends to test whether the "urban heat island" effect might have biased the conclusions; since they saw the same trends when looking at rural areas only, they concluded that it didn't. But that isn't the only criticism Anthony Watts made of the individual station data: he claimed that the locations of many individual thermometers, urban and rural, were poorly chosen (the classic case is one that was placed in the hot air exhaust stream of an air conditioning unit). The Berkeley project did not go and eyeball individual stations, as Watts did, so they had no way of assessing this effect.