You almost couldn't wish for a better test of Rabbinic influence. The Rabanut harashit and Harav Ovadia Yosef (The defacto chief rabbi) ruled that Lag Ba-omer should not be observed on the 33rd day of the omer, since it is Motzei Shabbat. The fear is that it would cause mass desecration of the Sabbath by security forces and I suppose some less frum Jews. However will the Israeli public really be willing to delay the fun of setting stuff on fire?
I've posted in the past my own opinion that it is overestimated the amount of influence Rabbanim actually have over the religious public. The test case in my opinion was the lack of any mass "refusal" by religious soldiers to follow orders during the Hitnatkut – despite months of rabbinical priming. However in this case we are dealing with a purely halachic matter – and so this should be a no brainer for the religious public. Additionally the very public nature of the bonfire should make it easy to see what the chosen result really is.
Somehow I suspect that come next week on the 33rd day of the Omer, I will see many a bonfire grace every spare spot of land.
Might be interesting to see if anyone tries to keep both days!