Its any new idea for some isnt it? I think you need to think through very carefully exactly what this might mean - not just jump at the fact you wont have to find baby sitters for the summer or for some teachers think its the magic bullet that will fix your exam results or your SAT tests / progress grades. Let me tell you now, there is no magic bullet.
I worked in a school where they tried this ( very deprived rural school). It did not work. Yes, initially it seemed that there were benefits in academic achievements but soon it became clear that they children were having more time off for ( alledged) illness than before. Whilst there was some initial omprovement ( and change will bring that kind of improvement) in results , they fell back the following year and were even slightly worse.
Everyone thought it would benefit parents but even they complained about the long half terms and child care m so the issue was just re distributed.
At the end of the day they changed back because it simply was not popular with parents or children or even teachers , many of whom didnt seem to feel they had any holiday at all, were permanently tired and had more time off for illness also.
Thats just my experience of what happened. It was an experiment and it was a three year one off plan which was dumped as failure at the end.
I cannot say if there were any useful social spin offs like less vandalism.
Most countries have longer holidays that us and they still out perform us in the league tables so lets get real. OK a few countries do take shorter holidays and perform ( lets just say SE Asia for example) but they are few in number and if you look at the culture of those countries you will see that their attitude to education is very different. Kids from SE Asia do well in our system regardless of the long holidays ( and they love those holidays too once here) so problems in Britain wont be fixed by a few cosmetic changes to holiday patterns. Its deeper seated. Its in the attitude of children, the attitude of many parents and in the stupidity of teachers if I might make so bold, who do not not follow good educational practice when teaching. They are full of eduspeak and new methods and they dont seem to work. Its all fanciful , just as the holiday magic bullet is a fancy.
Seen it , done it, got the tee shirt and the DVD is an ineffective bird scarer on my bean patch.
Its just one more nail in the coffin of why I wont be sending my own DS to a state school any time soon.