As I wrote about here, you can earn 50% bonus when you transfer Membership Rewards points to Delta Airlines and 25,000 MQMs if you transfer at least 50,000 points. There is also a 30% transfer bonus out there for transferring Membership Rewards points and it has been confirmed that these are stackable.

Do the following:
1. Register for the 50% transfer bonus for first time transfers.
2. Register for the 30% transfer bonus.
3. Make sure the promotion shows up here
3. Sign up for Platinum American Express Card (you may need to clear cookies to see the bonus offer of 50,000 for $1k spend)
4. Add your Delta Skymiles account to your Membership Rewards profile after approval.
5. American Express will let you borrow the 50,000 Membership Rewards immediately.
6. Transfer the 50,000 to your Delta account.
7. Spend $1k on the card.

Final tally:
$450 membership fee
Free lounge access
25,000 MQMs and Silver Status for two years
$200 incidental credit (for airline fees) on your favorite airline
90,000 Skymiles