Nikon today has posted a free updater that upgrades any 4.x version of Capture to v4.2.
Capture 4.2 is a fairly significant update to Nikon's primary RAW file processing and camera control application. It adds support for NEF files from the D2X, as well as control of the D2X over a WT-2/a wireless connection. Also new is improved noise reduction processing, a beefed-up Multi-Image Window, new Photo Effects and numerous tweaks to the colour and tonal adjustments tools in the program.
The 4.2 updater is free for licensed users of a previous 4.x release of Capture. Capture 4.2 is not yet available in a trial version, while the release notes on the Nikon USA web site suggest that the updater will only work on actual licensed copies of the software, and not to update an earlier trial version to 4.2.