In September 2010, we had an 8:10 am ADR at Akershus and were staying at the Poly. We arrived at the TTC monorail station at around 7:30ish am. They started testing the monorail before 8:00 am, but it did not start running until 8:00 am. We boarded a few minutes after 8 and arrived at the Akershus podium for our 8:10 am ADR at 8:30 am. There were more than a dozen families with little girls in princess outfits staying at the monorail resorts who also had pre-8:30 am ADRs and we were all late.
If there is a bus that goes to Epcot pre-8:00 am, it's not well-publicized. I wonder if anyone has actually *seen* an early Epcot bus from Poly.
We had a car and should have driven, but by the time we were at the monorail platform at the TTC, we figured we would not save that much time going back to the Poly, getting the car keys out of our safe, going to the parking lot, driving to Epcot, and then parking.
We also had issues waiting a long time at the Poly bus stop for a pre-8:00 am bus to AK for an 8:05 Tusker House breakfast. Eventually we decided to walk to TTC and ask someone there. After a 10-minute wait at TTC, we got a bus to AK (there are buses to DHS and AK from TTC). TTC seemed a better choice to AK because many employees take early public transit to TTC and then switch to Disney buses there. We arrived late to Tusker House, but not as late as Akershus.
If I were staying at the Poly again with an early ADR at Epcot I would definitely drive or take a cab or choose a time after 8:30 am. Trust me, you don't want to be up by 6:30 am, get all dressed up, only to wait 30 minutes for the monorail to start working.
P.S. - I had also read in here that some thought that the EP monorail started at 7:30 am, and if the monorail wasn't running they would have a CM directing us to an Epcot bus at the TTC. Well, since they were testing the monorail, we originally thought it was running. Also, there wasn't a CM at TTC directing us to an Epcot bus. So, don't be silly like us and know that it doesn't run until 8 am, they just test it before. There is probably a bus from the TTC to Epcot early because they need to provide transport fo rthe employees trying to get to Epcot, the same way they provide transport to AK and DHS throughout the day. HTH!