The blockade hasn't stopped weapons entering gaza and is in fact a smokescreen. By deciding what goods can go in and out of gaza and more importantly prevented 1.5 million people freedom of movement is because the siege of gaza supports the economy of Southern Israel. Israel could force the issue overnight by sealing it's border and refusing all exports saying they can go throught the Rafah crossing. Allowing the water treatment plants and power station into Gaza (something they have prevented for two years) The fact is without gaza Southern Israel's economy would collapse.
Egypt to hold parliamentary election in 2 phases starting Oct 18-19 (Reuters)
from the article: Netanyahu to Gaza flotilla probe: IDF coordinated the deadly raid