We stayed at the Regency Suites last year. Yes, it is right down the street......about 2 miles. We got on the MARTA (which is right next door to the hotel) and took it to the next stop, which is just a block from Earthlink. Much easier on the legs, since it seems that no matter what direction you are walking it is all up hill. If you are going to ride the MARTA a few times, it is probably cheaper to get a 3-day visitors ticket than to buy tokens each time. We found that out the day we were leaving Atlanta last year.
Have fun!
Trisha