From Java Verified: NEW! R&D Signing. Process:

1. Register
2. Request a Publisher ID ($200 US per year)
3. Sign your application with Publisher ID
4. Submit - and receive an expired signed application
5. Change date on the device to day of signing - 7 days
6. Install on device for R&D testing

Sources:

• javaverified.com
• developers.sun.com, TS-5682

The 10-year valid Java Verified signature still requires submit for testing. The table of supported devices seems updated for Nokia and Sony Ericsson, but not for Motorola, LG and Samsung.