1. It would be nice if the Regular Expression and Ignore Case checkboxes were synchronized between Find and Find in Project (the find and replace text are, so it seems these checkboxes should be as well).
2. I was somewhat surprised to discover that regular expressions can match across multiple lines. Or rather, I was surprised that TextMate feeds the regex engine the entire buffer instead of a line at a time. This is powerful, but it would also be nice to have a checkbox to force TextMate to feed the regex line at a time.
j.