General, the logic I see (and yes, I'm an idiot for using the words 'logic' and 'airline management' in the same post) is that in today's airline market you buy another airline in order to add profitability to your airline, not to reduce competition. This is because in most markets there isn't that much competition anyway what with the former big six (or seven, or eight) are now down to the big three. The cost involved in a merger will never come back in the way of increased fares via reduced competition. So airline managements today are looking at merger as a way to expand into areas and markets they don't already serve.
That means if someone were to buy HA, it would be because they don't go (or can't go) where we go now on their own. With the relative size difference between DL and HA, and the premium placed on HA because of our profitability and cash-on-hand, I don't see any way DL would profit by gobbling up HA. It would be cheaper to buy their own planes and fly them where we do without the added expense of a merger. And as it's been said before here, HA's profitability would probably tank if they were bought, because no other airline would sustain the HA customer service & experience as it currently exists, and those areas are exactly the reason HA is profitable in the first place.
After saying all that, I'd give it maybe a 60/40 chance against a merger, mainly because those words 'logic' and 'airline management' rarely appear together.
HAL