Apparently after all these years, Kurata and Co. are starting a new R.O.D series--another manga, titled "R.O.D -R".

Source: http://www.animenewsnetwork.com/news/2011-10-27/new-r.o.d-project-planned-for-super-dash-and-go-mag

Yomiko's in the ad so presumably it will largely be focused on the Die-cast rather than the Dream-cast. Although it would be interesting if they continued to combine the two as in R.O.D the TV. I really would love to see a follow up to the anime, but the manga in the past have taken place in their own little continuity, so my guess (total speculation here) is that if R.O.D -R continues anything, it'll be from the previous manga.

OTOH, even if the manga isn't connected to the anime, if it does well in Japan, maybe we can get an anime follow up too....