Well, let me update here with my progress on the guides...
Introduction to Marth - It's nearing completion. It'll be due within two weeks after Brawl's US debut. Note, this is not going to be an in-depth guide. It'll cover the basic play with Marth, and what techniques and strategies you'll need to play Marth at a casual to semi-competitive level.
Marth Match-up Guide - This here is a hard one. I'll post it within one month and add a lot more to it as I play more. This is not going to be just one section in some guide. This will be fleshed out to the max, to the likes never seen before. All competitive Marth players can message me comments on Match-ups. It'll really help, and I need the help.
The Competitive Marth - This is nowhere near done. It'll have percents, damage deterioration rates, a general idea of how to play Marth at the current Metagame (Yes, I'll update this at least once a month), detailed explanations on each move and how to use them. It'll also contain a combo guide, although I doubt that will be very long. The guide will be updated continuously, and I'd appreciate all competitive players thoughts on strategy with Marth.