Former MK Avrum Burg, son of former NRP leader Yosef Burg Z'L, seems to have created a rather large commotion with an announcement that he intends to break his fast halfway through Tisha b'Av and have a Seudat Mitzvah with his family, "since Jerusalem is no longer destroyed, but built up and flourishing, and because the people of Israel control their own destiny."
Predictably, the comments on NRG are extremely hostile, accusing him of making up his own religion, being a shameless publicity-seeker, and -- the ultimate insult in some circles -- being a 'Reformi,' or a Reform Jew.
In fact, what Burg (who, to the best of my knowledge, davens at a masorti shul) is doing is relying on a Conservative Tshuva which says exactly what he's arguing. See the full thing here (in Hebrew) or a short summary in, of all places, answers.com.
There is actually also a very good Conservative tshuva by David Golinkin against this idea, which you can see here. I've only skimmed over it, but very broadly it approaches the question historically (showing that the people fasted on Tisha b'Av even while the second temple was still standing and when the Jews were sovereign), halachically (showing that there's no halachic concept of stopping the fast midday -- it's all or nothing -- and that you cannot treat Tisha b'Av seperately to 17 Tammuz, 10 Tevet etc.) and philosophically (arguing that the biblical condition for turning these fasts into days of happiness has not yet been fulfilled, mainly as we do not yet have a third temple). This is also, incidentally, not the first time this discussion has come up. In England, for example, in 1968 or '69, a new* rather fine translation of the Tisha b'Av kinnot came out (the Abraham Rosenfeld edition), in which Nachem was amended to reflect that fact that Jerusalem had been 'rebuilt.' After a big fight, it was changed back again.
As far as I'm concerned, (much as some of us would like to...) it goes without saying that cancelling any portion of Tisha b'Av is, at this point in time, dubious, to say the least, and outrageous to say the most. It is one thing to celebrate the rebuilding of Jerusalem, which you can do on Yom Yerushalayim or Yom Ha'atzmaut, and another to play down the historical memory of the city's destruction, to ignore that fact that its revival, without the temple, is not yet complete, and to tamper with what is one of the most seminal, and deeply rooted and evocative days in our calendar. Eating a 'Seudat Mitzvah' on the day, moreover, is what the term 'sacrilegeous' was coined for.
Perhaps in the ecstacy of the aftermath of 1967, sentiments in this direction were understandable, if misguided. It's hard to see Burg's statement, however, in anything but a political and social context. He is deliberately making a public statement about where he stands, ideologically, on Israel and Zionism. Why would he bother? Apart from publicity-seeking, I'm guessing this is, or this began as, a dig at the haredim who don't celebrate Yom Ha'atzmaut etc. They're pareve about the state -- he's going to reaffirm just what it means to him....
Either way, I am simply astounded by his truly awful timing, remarkable even for a failed politician. First of all, Tisha b'Av is about to take on a new significance and new resonance for a large portion of the religious population, who from now on will forever associate it with what they perceive as the national tragedy of the disengagement. Then, you have the country at real risk of civil war, wallowing in needless hatred -- and he wants to eat a Seudat Mitzvah on Tisha b'Av!?!?!?!?
*The copy of the Rosenfeld edition I'm
holding in my hands at this moment says the first edition came out in 1965
-- presumably this was a second or third edition.