Apparently there's very few details yet, but President Barack Obama is planning to visit Miami on April 15 to help the White House's political wing Organizing for America. Sounds like a fundraiser.
Naked Politics points to this email from the Democratic Party:
We have exciting news and wanted you to be the first to know. President Obama will be in Miami on April 15th to help Organizing for America and the Democratic National Committee get the resources we need to continue the progress made in the President's first year in office. So much has been accomplished and much more is on the cusp of being done to help America's families succeed and flourish. We need to do our part...This is not a fire drill. It might be the only event Miami gets with the President this year. We need YOU!