I would take a trip to the dirctpc forums on the news groups first and have a look at what others are saying first. There is also a web site out:
http://www.direcpcsucks.com that has the feelings of different DPC customers. The largest complaint seems to be when you download a certain amount of files (nobody knows how much yet) your bandwidth is cut to a trikle. I would think that wanting DPC would mean that you want to download lots of "stuff". This is the ONLY reason why I won't go with DPC. The price of equipment is pretty low and I may also be able to use my exsisting equipment. But why bother if I can't download what I want, when I want. There is an alternative out now at:
http://www.tdenney.com/Lower price in the long term and they don't seem to care how much you download. The initial price of equipment seems a little steep though.
There are also two way high speed sat/internet service coming out next year. You then won't even need a phone line or isp. From what I read they are targeting people in areas that don't have cable or dsl access and people with dsl access that want to keep the speed at a lower monthly cost.
But I would, with out a doubt, think twice about DirecPC.