Will U5 deprecate parts of the API and remove the unityscript and boo?
No language depreciation.
Some parts of the API which are previously marked as depreciated will be depreciated like isOrthographic becomes Unity - Scripting API: Camera.orthographic - But it’s been marked with a yellow redundancy warning for a while no so no surprises really - is expected and widely known this would occur.
There are changes in 4.5 afoot with 2D physics such as BoxCollider2D.center becomes offset instead, but anyone working in 4.5 already knows this.
Minor stuff.