This background is to illustrate how Singer et al distort things. The new reconstruction only runs to 1960 as did earlier ones based solely on tree-ring density. All the other long series (Mike's, Tom Crowley's and mine) include other proxy information (ice cores, corals, historical records, sediments and early instrumental records as well as tree-ring width data, which are only marginally affected). All these series end around 1980 or in the early 1980s. We don't have paleo data for much of the last 20 years. It would require tremendous effort and resources to update a lot of the paleo series because they were collected during the 1970s/early 1980s.
It is possible to add the instrumental series on from about 1980 (Mike sought of did this in his Nature article to say 1998 was the warmest of the millennium - and I did something similar in Rev. Geophys.) but there is no way Singer can say the proxy data doesn't record the last 20 years of warming, as we don't have enough of the proxy series after about 1980.
http://www.co2.science.org/edit/editor.html takes the argument further saying that as trees don't see all the warming since about 1960 the instrumental records recently must be in error (i.e. this group believes the trees and not the instrumental records). This piece by Idso and Idso seems to want to have the argument whichever suits them.