I haven't heard of any significant changes to copyright law, just that authorities are going to start enforcing them more actively.
Just last week 11 people were arrested across Japan for piracy. The copyrighted materials include: Ranma (tv series), Dragon Quest (DS game), a Korean tv drama, various music, Death Note (manga), Wii Music/Sports Resort, movies, and various tv anime shows.
Code:
http://www.yomiuri.co.jp/net/security/goshinjyutsu/20091204-OYT8T00979.htm
The arrests were made based on tracking file sharing through the ShareEX P2P app, although this is not the first arrest of its kind (for Share or its predecessor, Winny).
However, so far there is no precedence concerning anyone
outside of Japan using ShareEX (or any other P2P app distributing Japanese copyrighted content), and since much of the said content is
not easily accessible outside of Japan, a certain amount of piracy is inevitable, so authorities will most likely be lassaiz-faire (which is why sites like TokyoTosho and JPopSuki have thus far been able to operate rather freely). It should go without saying that high-profile content (extremely popular, expensive, or new releases) runs greater risk than low-profile content.
If there are going to be any big changes, I would look towards the big players first (independent sites lik AO, TT, JPS receiving cease-and-desist letters), and a move on trying to shut down Share and Winny.
The article (linked above) does say that starting Jan 1, 2010, "copyright infringement through downloading will be considered illegal", as a revision (amendment?) to the existing law which stipulates that downloading of copyrighted material without having a license (for the content) is illegal. Personally I don't see how the minor revision in the wording will make it any more effective in actually stopping piracy.
For anyone who wants to stay on the safe side, you can switch to PerfectDark (the eventual replacement of Share), which is significantly more secure and (at least technically) makes it nearly impossible for authorities to track people down.