Under normal circumstances you should get them this year - maybe about 4-6weeks after you make PM. But with the merger, I would say these are not normal circumstances so I'm not sure.
If you do get them this year, they will be valid until Feb 2011. And under the current SM program you should get 6 PMUs.
You might want to call DL and see what they have to say.
If you have current tickets scheduled to be upgraded with miles, you can use the PMUs if you get them in time.