Definitley agree with don't overdress.
However this depends on where and how far you run. If you run 3-miles round the block then don't worry. If you run trails in the dark 2-miles from the nearest road and therefore quite some time to get support even if your GPS enabled blackberry can summon help then maybe be better prepared.
For me tights will come out in December and v.lightweight jacket probably slightly earlier.
I do have a v.light Nike Hat that I stuff in a pocket. Popping it on if I get cold soon warms me up. If really cold I may wear it to start but remove before you overheat and get it sweaty. Useful if you have a running issue. DoI don't use gloves but suggest you again go v.lightweight.
So agree with the don't buy anything/everything until you need it. Unless you live in Northern Scotland and 2-weeks travel from a running shop.
Thin hat, maybe thin gloves (Nike do a gift pack). They are easy to stuff in a pocket or waist band. Add extra bits as you get chilly. The proper runners kit doesn't match and hasn't been planned, it has evolved.
Dave