Mileage valuation is oft-discussed and there are differing opinions; my own benchmark is about 1.666 cents per (though I'm thinking of lowering to 1.5 cents). I go to Asia a lot, so the pay-or-burn issue comes up quite a bit.

When burning miles, I make sure to milk things like stopovers or open jaws that come with awards but not lowest-fare paid flights. Stopping in HNL en route to Asia, when I can get it, is great. Am also working on a BKK vacation via Europe routing on Star Alliance (for 70K coach rather than 60K) with about a 5-6 day Europe stopover. 10K extra to tack on a Europe stop to Asia seems like a bargain; the only drawback is having to fly 2/3 of the way around the world in both directions. Stuff like that, if it's your thing, can add a lot of hidden value to award tickets.

It's definitely risky to keep piling up miles; even if no bankruptcies affect things, I think the ratio of unredeemed miles to seats will continue to. Some airlines like CO are said to be so bad about "standard" award availability that they've effectively devalued miles by 50% by making unrestricted awards the only way to go. Lots of baby boomers retiring in 2011 and after could be using fat mileage balances at half, a third or even a quarter of the value the miles had when earned.