Just heads up for those who may not visit DL forum, or those who think the No Expiration on DL miles is a great plus (versus other programs where there are gazillion activities one can perform to perpetuate the life of the accounts).

Here is a drastic change on allowed change on DL rewards which makes it even more restrictive than BA's program.

http://boardingarea.com/blogs/viewfromthewing/

<<Today, Delta announced that award tickets would in fact be totally non-changeable and non-refundable within 72 hours of travel. Very odd indeed that they would make one change to the policy and then two weeks later make another, more severe, change to that same policy.>>

No change is allowed 72 hours before departure.

<<Since Delta says that there were 1,000,000 seats booked 72 hours out but not flown (again, no mention of a time period from which this number was taken), that means 1,000,000 award tickets that would no longer be redepositable. Who says Delta Skymiles don’t expire?>>

If you dont cancel the award before you fly, you lose all the miles.

Since DL tends to release its Saver tier award very close to departure, this essentially means you cannot do so even if low cost award becomes available close to departure but within the 72 hours window.

Dont know if the top elites can still cancel inside the 72 hours without penalty. Those who are elites naturally would have already been in the know. The rest of us would need to be much more careful when using DL miles - making the Skypeso further lower value than other airlines' currencies.