I have a 12,000 mile trip coming up and have the choice of banking the miles in my Delta Miles account or One Pass account. I have accumulated more than 50,000 Delta Miles and hope to use them one day, but would need more for a good foreign trip. I have nearly 10,000 One Pass miles and 12,000 more would still not get me all that far. However, with Delta in bankruptcy, I am wondering if I should be trusting that Delta miles will be usable even after I accumulate what I need. They are currently usable in the One Pass system, but not combinable with Delta Miles. Any thoughts?

I think you're good on Delta for a while, as they're getting the labor agreements and fares are going up and the situation for the industry as a whole is improving. If there's a reversal it won't happen suddenly (unless they uncover some Enron-like fraud, which I don't think is likely).

DL has been repositioning its route system and doing new routes where there's little or no LCC competition, so if you want to redeem 60K+ miles for two tickets you could have good opportunities on new routes early on. DL has added a bunch of Caribbean and Mexico routes out of ATL that they often have to discount because other airlines are also adding Mexico/Caribbean flights. Getting 2 tickets somewhere like SXM or PUJ shouldn't be too bad. Recent adds to OGG or KOA gave people a chance to go to Hawaii on standard awards (70K for two), though those are filled out by now.

Book delta then use the mileage for hawaii.

Welcome to FT, zephyrus. Glad to have you with us. I think what you do depends on your immediate plans and a few other factors. First, I wouldn't worry about a DL bankruptcy unless you don't plan to use the miles for quite some time. Second, you may find some difficulties on either DL or CO with getting award tickets to anywhere as many FTers complaing about availability on both of these airlines as being among the worst. That said, with some flexibility and persistence I wouldn't consider that a major obstacle. I've had pretty good luck with DL so my vote would be for them.
Third, if the upcoming trip miles go to DL you'll then have enough for two 30K tickets which could get you and another to Mexico, Bermuda and the Caribbean as well as to the continental US and Alaska. You'd need 70K for two to Hawaii so that would not be much more as well. The 12K with DL will still leave you about 3K short of even a ticket within the Continental US although if you could do better than that if you wanted to travel on some of the CO weekend specials that allow much less mileage for a trip but with a cash supplement needed with these miles. Check out the CO website for details. It just depends on how you want to use the miles.

You also can add a lot of miles by getting a DL or CO affilitated credit card. I believe you can get up to 17,500 miles with a DL card and probably something comparable with a CO card. If you do a search on the CO and DL forums and use "credit cards" as a search term you get some good info. You can also check out the Miles Buzz and Credit card forums for similar information. These miles would take a little while to post so if you're in a hurry this approach may not work.

Finally, I would recommend you go to the CO and DL sites and check out their partners in their respective FF programs. There are many, many car rental, flowers, stores, gas and other options that will help you build miles quickly, especially if you spend using the aforementioned airline affiliated credit cards, some of which will provide double and triple miles opportunities on occasion. You will be amazed how fast the miles build up when you charge virtually everything rather than spending cash. With the caveat of course that you need to be certain that you can pay off the cards in full each month to avoid high interest rates. Our family approach is to save the miles for longer international trips and wait until we have enough for business class awards before we use the miles. We grin and bear it on shorter domestic flights knowing we'll have relative luxury on our trip overseas, providing a great start and finish to our longer vacations. For you or others this may not be your preference for use of miles but many FTers swear by (and some "at") this approach. In any case, welcome again and good luck.

Forget Hawaii, go with southern Cal! ;-)