Time Warner is rolling out PowerBoost throughout their terretory to Turbo and Standard customers. That explains your boost in speed -- It's all fun and games in a Team Fortress 2 battle until your sentry gun is sapped by the Spycrab!
Yeah I figured though that for awhile it was just turbo customers that got it but then they added it to us too. Guess it's not a bad little surprise, but like the other guy said wish the upload was better. My apt gives me roadrunner/analog 2-99 cable with my rent so I'm actually kind of stuck with time warner cable because if I did get u-verse (which I don't think is in this area of charlotte yet) I would still have to pay for the other.