I know its not done yet, but from one of Cakers previous posts, one of the things hes looking at doing with the new multiple linodes on a single account, is have floating ip addresses which could work in your situation so if one host goes down the other just takes its ip(s) and does all of its work as well..
Im not sure if there was an ETA to this being implemeneted but it might be something worth following up on.
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"Diplomacy is the art of saying nice doggy whilst looking for a really big stick"
"In my experiece, any attempt to make any system idiot proof will only challenge God to make a better idiot"