The JUL Logger API has methods such as:

public void log(Level level, String msg, Object params[])

This makes the code somewhat ugly, whereas converting that last argument to a varargs would make it lovely.

// A bit clunky
LOG.log(Level.SEVERE, "Failed to deploy bundle {0}\n{1}", new Object[] { bundleName, e });
// A bit nicer
LOG.log(Level.SEVERE, "Failed to deploy bundle {0}\n{1}", bundleName, e);

Another little pet peeve, I prefer not to use the log methods, but instead the "warning", "severe" etc methods because it makes the code very readable and also means that I don't have to either statically import "Level" or prefix everything with Level. However these methods are missing variants for handling formatted text, which makes them less than useful.

// Well, with varargs a bit nicer
LOG.log(Level.SEVERE, "Failed to deploy bundle {0}\n{1}", bundleName, e);
// Nirvana
LOG.severe("Failed to deploy bundle {0}\n{1}", bundleName, e);

And just to drive home the point:

// What I have to do today:
LOG.log(Level.SEVERE, "Failed to deploy bundle {0}\n{1}", new Object[] { bundleName, e });
// What I'd like to see
LOG.severe("Failed to deploy bundle {0}\n{1}", bundleName, e);