I would say benefits of long term play is
Emotional Development- the children would see other children and other adults express themselves in different ways each day and they will come accustomed to it and therefore beable to express themselves according to their feelings.
Social Development- As they will be around children and adults all day they will develop there social skills. They will need to ask adults to go the toliet and for help with games. Also they will play alongside with the other children and learn to share and learn by other childrens expressions if they are doing the right thing.
Physical Development- In long term play they will build upon this skill lots. Playing ball will help their gross motor skills, markmarking will improve their fine motor skills. With most physical activities being active they will improve co-ordination and balance.
Cognitive Development- As time goes on the children will start to think for themselves and start to understand things alot more quickly as they will be used to it. So if they are in long term play they will develop this alot quicker.
Hope this has been a little help.