One bug, that have prevented me from using Java on the desktop for several years, is that it up until
the latest j2sdk1.5 beta, it was impossible to write tilde and many other characters common in many Euoropean languages on non windows platforms.
This sort of took the advantage of crossplatformness out of java and you were better of usint e.g. QT if you needed to develop cross platform applications.
And as far as I know there was no good workaround for these bugs.
Now I'm glad to see that at least this bug is gone and I will reconsider using java again. The new versions also seam a lot faster than what they were a couple of years ago.
Now if only the licencing could be a little less restrictive. It doesn't need to be open source but it would be nice if both sdk and jre could be included in free software like Linux distributions that would probably be very beneficial to Sun and Java.