The new conforming loan limits are assigned by the county itself, not a specific region within the county. Currently, there are essentially 2 conforming loan types in Nassau county - Standard and Jumbo. The standard conforming loan limit is $417,000 and the jumbo limit is actually $729,750, not $625,000.
Also, keep in mind that the jumbo loan limit also applies to an FHA loan so you can actually go with an FHA loan in Nassau County for only 3.5% down vs. putting at least 10% down for a conforming loan.
If you have any questions about loan products or rates, feel free to contact me.
Bank of America Home Loans