Firstly, I'd suggest if you're going to think about going this route, read, read A LOT about it, and not just those saying 'It's the new wave', etc etc. It's probably not the answer to all your multi million selling dreams, but, if you go in with the right attitude, it can be rewarding.
From what I've discovered
(some of the) Pros:
You're your own boss.
No one to give you a crappy cover that you hate etc
Complete creative control
You get a higher % of the sale price
(Some of the) cons:
You are your own boss -- and you're bankrolling this. Editing, cover etc. If you don't pay for these, or at least don't get pro standard, it will really show. You're out of pocket unless you sell well. You take the risk the publisher normally does.
You also get to do all the rest that a publisher usually does: marketing, promo, cover copy, formatting, file conversion...the list goes on. There's a reason many successful self pubbers take the traditional deal when offered -- it gives them more time to write
Sales: Almost certainly will be less. A lot less. Meaning that while you get a bigger %, overall you'll probably make less. A few Self pubbers do have pretty good (or tremendous) sales, but the vast majority will struggle to make double or triple digits. If your book is in bookshops as well as online, being backed by a big pub with their knowledge of PR and marketing, then you have a much better chance of sales. (Not everyone has internet access , not even in the States, where I think it's at 20% that don't. That's a lot of people who can't get your book) You're also more likely to get reviews (many reviewers won't look at SP) etc etc
So, think about it, research, a lot, decide then. Can you afford to get edited, a good cover? Are you good at promoting yourself? Do you enjoying paginating MSs? Do you just want it out there, or do you want good sales? (Or both?) How much time do you have to promo? Is creative control the most important thing?
All questions only you can answer.