Is there a way to setup Eclipse + gnu gcc + debugger for the ARM Cortex-M3/M4 based microprocessors (e.g., Stellaris, Kinetis)?
If toolchain is gcc based and debugger gdb based, then probably yes. Just use eclipse with CDT, set up cross compile project, enter toolchain prefix (like arm-eabi- or something) etc... When compiled use create "gdb hardware debugging" launch configuration, enter proper gdb command to use (probably something-gdb) and you will probably be fine.