If you want to catch up on all that's been going on in New Testament textual criticism in the last few years, there is no better resource than Hugh Houghton's recent article in Early Christianity 2 (2011) 245-268. Those with an institutional subscription should click here. Otherwise, the article is available (minus final format) from Hugh's own institution. It's also a good overview of the status quaestionis.
Well done, Hugh!