Another example is the two decks produced by Raven Grimassi and Stephanie Taylor, the Hidden Path deck and the Well Worn Path deck. They consist of 40 cards each, and can be used together or independently. Unlike the Tarot, they are all 'picture' cards- without a number or suit designation, and each card has a meaning related to some aspect of Paganism. It's an interesting take on using cards and symbols for divination, and not a bad one!
Perhaps the main difference between an oracle deck and a Tarot deck lies in their names- an oracle speaks not to a situation, but to a specific person. Thus, the focus of an oracle deck tends to be much more centered on the individual- instead of saying "this", as a Tarot deck does, taking into account all the factors surrounding a situation, an oracle deck will say "you", addressing the specific person, and often has a greater focus on the individual and their internal state. The oracle deck will focus on thought processes, patterns of behavior, and how a person reacts to their world, while a Tarot deck has its focus on the situation as a whole, and what external as well as internal factors influence a situation. This isn't to imply that one is superior to the other, merely to note that the different focus can assign a more specific use to each one. I've found that they can be used together, as after all, we live in one world, governed by one set of rules, complex and multifaceted though they are.