Many of the threads about Java on this site are started with trollish negative statements about Perl in comparison to Java (often quotes from managers or co-workers). These are bound to draw angry responses. However, if you look at threads along the lines of "what other languages should I learn?" you will find many people recommending Java.

I think most serious programmers should learn Java these days, because there are a lot of interesting ideas being published in articles and books about Java. For example, Martin Fowler's book Patterns of Enterprise Application Architecture has examples in Java.