Definitely check on the actual number of cells in your batteries. Nikon's EN-EL3 and EN-EL4 batteries both have 3 cells making them 0.9g and 2.25g of lithium content respectively. Either way, they're way under the 8g threshold.
The TSA has clarified the wording of the new rule. The updated text reads as follows: "-Under the new rules, you can bring batteries with up to 8-gram equivalent lithium content. All lithium ion batteries in cell phones are below 8 gram equivalent lithium content. Nearly all laptop computers also are below this quantity threshold. -You can also bring up to two spare batteries with an aggregate equivalent lithium content of up to 25 grams, in addition to any batteries that fall below the 8-gram threshold. Examples of two types of lithium ion batteries with equivalent lithium content over 8 grams but below 25 are shown below." http://safetravel.dot.gov/whats_new_batteries.html With this clarification, we don't have to worry about the number of camera batteries we fly with... Now all we have to do is hope that the screeners will know that our batteries are below the 8 gram limit...
Update: I flew from Washington Dulles to Bozeman Montana yesterday for my Yellowstone trip, and had no trouble with the batteries. They sent me right through security without even a question about them.
They're prob looking for the big camcorder batteries and external laptop ones. Or the personnel haven't gotten the memo yet.