One small victory! Turns out this was part of the transmission replacement, so it's still under MBZ warranty. The indy shop did their diagnosis and feel confident the torque converter is the cause. Looking through the grates of the bell-housing, they could see the torque converter wobbling.
Next, stopped by the dealer this evening and presented my case and all their paperwork. At first they claimed they didn't replace the torque converter. I said it had been replaced and was told at the time that the entire transmission needed be replaced. After looking at the paperwork they set-up an appointment and scheduled a loaner car for tomorrow morning. What ticks me off about the dealer is that they couldn't say, "oh, you're right - my mistake, I'm sorry." Instead the advisor set an appointment and arranged a loaner. In addition to the original paperwork I had the follow up invoices showing I came back twice (originally picked up the car on Friday and then came back the following Monday morning) complaining about the vibration. They charged me both times - errrggghhhh...
After setting the appointment they showed me a torque converter from the same model (had another E getting its tranmission replaced in the shop). They are guessing either the balancing weight came off the housing (a little lead weight soldered to the outside) or its shaft is bent. I tend to think it's the shaft since since the vibration was immediate from the first day I picked up the car (or maybe it's missing its weight from the time it was installed).
It goes in tomorrow morning and god-willing, this will be resolved by the end of the week. Keep you fingers crossed.