Virginia could still end up partitioned due to the fact that part of the state is on the other side of the Appalachians. It took a month to get from one side to the other.
If it didn't get partitioned, today the two states together have 10 million people, and have a GDP that is around the size of New Jersey (around Switzerland or Belgium), and this is with slavery holding it back for 30 more years than your POD and having been. Populations wouldn't flee the state, Richmond and Alexandria would likely become a bigger city, and it would become a big state in population and GDP, similar to Texas, New York, California, or Florida today. All of the gas, coal, and mineral wealth in the Appalachians would create an energy boom even bigger than Texas' gusher age.
Virginia would have the largest black population of any free state. If they are treated equally under the law (no segregation or sharecropping), Virginia could become a model showing that freed blacks could accomplish something. That would likely some time and education though.
The State would be socially conservative, but with a mixture of liberal and conservative economic policies (Lowish taxes, social welfare, big infrastructure spender etc.). It would become a buffer state, or a Chesapeake state, as opposed to a southern state.
Being surrounded on all sides, Free NJ and Penn to the north, and Free Virginia to the south and west, Slaves would constantly be escaping to freedom. Eventually the costs of losing the slaves and hunting them down will overtake the size of the benefits, and with strong social pressure from the surrounding states, slavery would be eliminated from the Delmarva peninsula.