Hey there,
unfortunately there isn't a realistic or expected return. I've seen some guys return 1000 pips in a month and others lose a 1000 pips in a month. Your success is determined by your commitment. You need to understand how the market works and what makes it move.
Personally, I'm doing fairly well. I've never really traded often, and I'm relatively new to forex. However, I do have basic TA skills and I escpecially understand fundamentals of the market. Three weeks ago, I was trading stocks and decided to "invest" for the long term in a handful of companies. Low and behold, the market took a huge dump and I was down almost 20%. I contemplated pulling my money and concentrating on school, but my buddy told me to take a look at forex. So I did! Over the past three weeks I've traded the USD/CAD and the EUR/USD. I've made my losses back plus some. I've also quit my part time job since I make more doing this a couple hours in the morning, and I can now concentrate more on school.
As for that 90% failure rate, its kind of hard to judge because there is no way to evaluate the commitment and effort of every trader out there. Some people research the hell out of everything (usually successful) and some decided to trade because they have a gut feeling or because the chart looks pretty (usually failures). I, for one, believe that if you commit yourself and actually put the effort in, you can make a decent chunk of change.
My thoughts,
Eric