First, I don't want to start a flamewar, and if you're a principal of MySQL AB, just hit -- and move on.

If you're interested in searching, you may run into some limitations with MySQL pretty quickly. If you are considering storing (and searching in) large blocks of text ( lyrics, books from Project Gutenberg, etc. then you may want to consider PostgreSQL and tsearch2 instead of MySQL.

You will probably find it easier to change databases at the beginning of the project than in the middle.