A rabbi* in Israel recently ruled that Ashkenazim who live in Israel do not need to maintain the Ashkenazi custom of refraining from eating kitniyos (e.g. peanuts, string beans, rice) (link - PDF).
My humble opinion on this matter is that there is nothing new in this ruling. It contains two main points:
1. There are opponents to the custom of refraining from eating kitniyos. The ruling quotes the Tur (a Sephardi), the Beis Yosef (a Sephardi) and R. Yaakov Emden (an Ashkenazi who grew up in the Sephardic community where his father was the rabbi). This is nothing new. You can see it in many different popular works, such as R. Shlomo Yosef Zevin's Ha-Mo'adim Ba-Halakhah. The ruling does not quote the many, many other sources who accept the practice, such as the Maharil, Rema, Gra, Chayei Adam, Mishnah Berurah, Arukh Ha-Shulchan, etc. etc.
2. Israel is a Sephardic country and therefore Ashkenazim are obligated to accept Sephardic customs when moving to Israel. This is an important question and I believe that the position advocated has merit except for one point -- timing. If this ruling had been issued 200 years ago, I think it would be valid. However, as Ashkenazim moved to Israel and established communities, their posekim ruled that they should not abandon their customs. The most famous such ruling is in the Pe'as Ha-Shulkhan (first section), in which R. Yisrael of Shklov argues that Ashkenazim have had a long, if limited, presence in Israel and therefore the country is like a city with two courts, in which each community follows its own court.
R. Nachum Rabinovitch put it well in his Melumedei Milchamah (no. 84):
One can question whether there is room for this custom [of refraining from eating kitniyos] in the land of Israel, since the ancient communities here did not practice as such and it is accepted among the decisors that the Rambam and the author [of the Shulchan Arukh] are the decisors for the land of Israel, and they explicitly permitted rice and certainly other kitniyos. However, from the time that other communities became established here, they retained their ancestral customs that they brought with them from various coutnries, and they have already practiced that the entire community follows its own customs. Therefore , there is no custom of the land of Israel that obligates them.By now, the Ashkenazic community has been growing for over 200 years and has maintained its customs. Now, almost 60 years after the establishment of the State of Israel, we are hearing a call for Ashkenazim to adopt Sephardic customs??? Did R. Avraham Kook eat kitniyos? Did R. Shlomo Zalman Auerbach eat kitniyos? They knew everything contained in this ruling and still kept their family customs.
In my opinion, the time for such a radical proposal is long gone. There are, I believe, more important windmills to charge against.
* If you'd like to get to know the rabbi who issued this ruling, see this video in which he launches what I consider to be a sarcastic and unfair attack on R. Shlomo Aviner - link. You can also see this essay by him on Jews and Gentiles, translated into English and posted on an anti-religious website - link.
UPDATE: See this article on Arutz Sheva of contemporary rabbinic authorities who disagree with this ruling.