Got an e-mail last night from Delta/Northwest regarding the merger. They’ve posted a SkyMiles/WorldPerks Integration Timeline here ^[1].

As a frequent traveler and WorldPerks Elite member, I highly value my Northwest Worldperks miles, so I found this extremely useful. 

Key takeaways:

• The required Saturday night stay to redeem Worldperks miles is gone. This is awesome.
• As of March 1, 2009, WorldPerks Platinum Elites and SkyMiles Platinum Medallions receive two reissue and redeposit fee waivers and pay $50 for every other instance. This is great. I’ve bought tickets with miles and had to pay the $50 redeposit fee when plans changed three or four times.
• In December 09, all 2009 WorldPerks Elite Qualifying Miles, Elite Qualifying Segments, and mileage balances will be transferred from WorldPerks accounts to their linked SkyMiles accounts to ensure proper status for 2010. WorldPerks is essentially dead at this point. 

See the full timeline and details here ^[1].