According to Ray Gan (read his blog), JAVA SE 7 code named Dolphin (The Dolphin Project) is to be started in late July on java.net. The release of Dolphin is planned to be in 2008.
Further non critical bug fixes, and API changes would be considered for this release.
The current version JAVA SE 6 code named Mustang is to be shipped in September this year. The current development means bug fixes only and is expected to have update releases every three months.