Ill give ya tha 411, k first you are bound to die but thats only if ya do something stupid and end up making it mad but you probablly already know that so now to the lifespan its only about 5 or 6 months and thats if ya got your water and all that near perfect! other than that not much more i can tell ya but like colin said post up your tank info and i will be able to give ya som more info!
Have a look at the thread called List of Our Octopuses at the top of the Journals and Photos forum. Scroll down through the list of bimacs and you'll come to Other Species. There are a couple of people keeping bluerings.