i was wondering the same thing...
deleted everything. (about a month ago).
nothing happened AFAIK.
all seems to be OK.
suggest you do it with no open apps.
(if you have a running app that is using some files in the TEMP and you delete it, might mess up the app or its data).
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien