My suggestion to anybody doing a MMO in flash is not to be discouraged. Sure it’s a HIGE task, and tons of people don’t ever finish the ones they start. But follow the basic advice given in this forum and you should do fine. A few years ago I wanted to make one and I decided to learn actionscript first by doing small games. I’m now about to finish my first MMO in a few months. You can check it out at www.zening.com/game . (hit quick play).
As far as the server goes, I decided to buy and host my own server at home. Utah has fiber optic so I’m getting 15mbs up and down for cheap. I hope it’s enough to at least get started.
Anyways, long journeys stat with one step. Don’t be discouraged.