While burning might sound like a good idea, I think it depends on the amount that you *want* to travel. I'm just short of 2 business class tickets to SYD. That is a trip that I would like to take in a few years when my daughter will be old enough to enjoy it.

Should I burn up my 180,000 miles now on 3 (at standard rate) or 7 (at saver rate) domestic tickets that might only be worth $200 to $300 each? Or should I hang on to the miles, even knowing that they will be devalued -- but still more valuable when used internationally than when used domestically? Perhaps by the time I am ready to actually go to SYD, I'll have 360k miles (for 3 first class seats), or I will by some coach tickets and upgrade using miles to business?

To burn miles, you need to have someplace to go that you want to go. Otherwise, I think its like burning money -- yes you know you dollars are going to be worth less tomorrow than today, but that doesn't mean that you literally burn them today.