Disney released the March 2015 Disney World operating schedule at the usual link: http://media.disneywebcontent.com/StaticFiles/ParkHours/WDWTravelAgent_march.pdf. Click refresh on your browser to load the newest version.
Average crowds continue through March 7th. Beginning March 8th, peak spring break season begins with higher resort prices and heavier crowds. This year, March 22nd-28th looks to be the soft spot based on regional spring breaks. Resort prices remain high, but crowds will come in at a “6 or 7” instead of an “8 or 9.” With Easter falling on Sunday April 5th in 2015, the busiest and most expensive week of the season is expected to be April 5th to 11th. Beginning April 12th, crowds fall back down to below average to average.
If you are flexible with your dates, look at the end of February into the first week in March or try to wait until at least one week after Easter.