On the SERPs of google.co.jp there is now an extra link next to English pages to get a translation of that page in Japanese. Like many new features of Google it also says 'BETA'. Not sure of that's also new, but also on the English Google there is a 'Translate this page' link for Japanese pages.
I just spent some time going over a few sites of mine with this tool. The Japanese rendered is just like any machine translation. It will give you the gist of the meaning, but a native speaker will tell you it's garbage. It makes just enough sense to tell you what's going on...no better than any other free machine translator on the market.
The difference here is that it's Google Japan doing this. It does give the impression of opening up the SERPs to the Japanese who are extremely limited by language. I'm surprised they've taken up so much space with the whole "Translate this page BETA" next to every result. I guess they could just add the kanji for translate if they decide to make this a permanent fixture in the SERPs.
Overall, I'd say this is a well meaning move, but it's not going to go too far. A native speaker of Japanese is going to use this a few times to check out a few sites and then get a headache trying to figure out the machine gibberish.
I think that this may give some more exposure to the Google translation tools. I know that I personally use the tools of other Japanese SEs for machine translation. Excite Japan [excite.co.jp] and Infoseek Japan [infoseek.co.jp] are two that come to mind. I don't use those engines for searching very much, but they're in my bookmarks for daily use of quick down and dirty machine translation. Google will probably get some mileage out of this.