Days are numbered till this thing gets locked, so here I go. If you value your 360, wait till a chip comes out with a switch. It saves you from having to buy another 360 for live & other legal exploits, and if you get someone who knows what they' re doing, you shouldn' t have alot to worry about in terms of the box malfunctioning.
A better alternative , is softmodding, never touching hardware, and popping in bootdisk after bootdisk. I' m cosmetic-modding my friend' s PS2 with a fliptop for just that purpose.
The best option of course is to wait for TGS, to see if they' re releasing a black 360!