Eh, no, but you might try using dimexpert if you have to dimension a lot of slots.
Old post, but this is an easy one now.
Starting in 2009 they added the Slot Sketch tool. It is one of my favorite sketcher improvements. If you use it to cut a slot then on the drawing you can use the Hole Callout tool just like with a hole (except it doesn't add depth or quantity).
It also puts in 3 temporary axes per slot (great for mating a bolt to the middle of the slot), and allows you to centermark the slot in different ways. And it allows for some new relations, so you can make slots equal in all dimensions with one relation. You can dimension slot length in 2 different ways (to center of each radius, or max outside length). Finally you have 4 different slot types (arc slot, centerpoint straight, etc).