On Feb 1, 2003 a new tax is added on to airfares, I think it is $2.50/segment or $10 per ticket - I can't remember which the Northwest agent told me. Taxes have increased so much on airfare over the past couple years, so keep in mind you may not find fares quite as low as last year. Then again, who knows! You know best what the generally going price is for the airfare during your travel period - if you are within 10-20 of that price, I'd consider it at this point.
Out of Detroit we can find airfare for 130-200 (sometimes less on very off peak, always more) to Orlando by vigilently watching - last week we happened to find airfare for $161.50 for April, which is an incredibly busy time to fly with the various school vacations and Easter.
If you find flight times and dates that work with your schedule, you are flying during a busy travel time, the price is within a range you are comfortable with (we were looking for anything between $150-200 during a busy travel time), then book it and don't look back. Even if it drops $10-$20, the peace of mind you have for booking it and being done with this may be worth your time and worry over catching the deal.
July still gives you time - and you are right, about 2 months out there seems to be a round of pricing to fill the planes. So the question is, do you want to keep on watching the fares, or are you comfortable with the fare? And once you book, don't second guess yourself by continuing to watch the fares - you will drive yourself nuts if by chance one day you see the fare at a lesser price (and that doesn't necessarily mean it's available, depending on your internet search locale).