The Rebug team, know from the ps3 scene, officially unveiled their all-in-one (Flasher, RGH, JTAG) Xbox360 chip on xaio360.com:
Features:
Opensource Firmware
JTAG Programming of onboard Xilinx via USB (No external programmer needed)
SPI Progamming of Xbox360 NAND via USB (No external programmer needed)
Fast swap between SPI and JTAG modes with a press of a button
External Oscillator (Wiring to HANA is no longer required)
Firmware upgradable for future XAIO 360 updates (No external programmer needed)
100% Compatible with NAND Pro v2.x (3.0 is NOT supported!)
Compatible with all Xbox360 models (Except Xenon and Corona boards)
Booting of unsigned code on Xbox360
Compatible with all Xbox360 kernel versions
Glitching of all compatible Xbox360 models is usually within 3-25sec
Easy 7 wire SPI installation for both PHAT and SLIM
Easy 5 wire RGH installation for PHAT, 6 wires for SLIM
Works as 6 wire JTAG-Interface using UrJTAG software (4 signals + power (TDI, TMS, TCK, TDO, VCC, GND)
*Required patched version of UrJTAG
Compact size of 47mm x 32mm (1.84 x 1.28)
Its a all in one kit built in-programmer and can dump the nand by its self !

Official Site: XAIO 360