From http://nirc.nanzan-u.ac.jp/publications ... anji_1.htm
Since I only recently purchased the 5th edition, this was nice to have pointed out to me clearly.In December 2010 the Japanese Ministry approved the addition of 196 characters to the "general-use" kanji list. 39 of these are already included in Remembering the Kanji I. The remaining 157 have been prepared as a special Supplement that may be downloaded here (1 December 2010 update). They will all be integrated into the Sixth Edition currently in preparation. For a sample of the contents, click here.
The site "Reviewing the Kanji" at http://kanji.koohii.com/ also supports these supplemental kanji as well, so you can really get the most out of all of the available material right now.
I suppose I might just have to pick up a copy of the 6th edition when it's available. I don't like having "outdated" materials.
I hope this can be as helpful to others as it was to me! Thanks guys!