Norman,
Since NX2 is still the current version of Nikon Capture, the 2+ year age of your copy shouldn't matter, though having used NX and NX2 myself in the past, I would still recommend you consider other alternatives, even if you like what your previous work with NX2.
However, whether you jump up to Photoshop CS5 or not, depending on your processing needs, I think you probably don't need to.
You might however want to consider Photoshop Lightroom as an alternative to Photoshop and a good comparison between NX2 and Lightroom 3 can be found here:
http://ishootshows.com/2010/01/22/lightroom-3-vs-nikon-capture-nx-2/Regards,
Peter
[EDIT] On the other part of your question, for NX2, there is nothing close to the same level of expertise anywhere that is available on LuLa in relation to Photoshop and Lightroom.