It's about a formal review stage (of papers, research proposals or other things) where some qualified scientists (ie 'peers') look at the work before it's published, give criticisms, corrections and suggestions where necessary, and perhaps say "don't go ahead" because it's not of acceptable quality.
It may be that, with the onslaught of climate change deniers, it will be better to make everything open (not just up to the CRU, of course - the data in this case comes from national meteorological organisations), and tell them to put up or shut up.
For instance,
there's a blogger who, fed up with the accusations from Anthony Watts and others that temperature gauges had been removed to distort the warming record, actually re-did the analysis himself to work out what effect the loss of gauges has had. It took him a couple of weeks, but he proved that the loss of gauges has had no noticeable effect, and that Watts and D'Aleo had lied about some things. Most importantly, it's clear that they had never even attempted to do any similar analysis before their accusations of fraud. They just saw that many gauges had stopped appearing in the global network, and then made up stories of fraud and data manipulation.
The blogger is now going to write this up as a paper - though, as he says, it may not be accepted for publication, because it doesn't show anything new in scientific terms, just that Watts has been unjustly smearing scientists without evidence. But he'll put it all out in the open anyway, because it's becoming clear that the deniers are not behaving like responsible scientists (hell, not that many of them are scientists), and so they need to be exposed as smear merchants who aren't actaully interested in the science, just in disrupting the work of actual climate scientists.