I snagged this from my favorite blog "We Break Stuff".  It is worthy of a republish because this is a common misconception that I have witnessed.  Interactive marketing boys and girls listen up for the real deal.

Tim O’Reilly has a post on the O’Reilly Radar
that caught my eye today. He mentions how Java developers at the
JavaOne conference showed signs of (and I quote) “envy and angst”
against Ajax, and follows that with “Java had the vision of rich web
apps long ago, and is still a great platform for building
network-enabled apps with great front-ends”.

Now the misconception here isn’t that Java is a great platform to
build applications front-ends (network-enabled or not), but that it can
be compared to Ajax. The two can’t be compared for several reasons.
Here’s two:

• The technologies behind Ajax alone (XML, Javascript) are not enough
  to build an application. Ajax is a means to an end - or part of it. It
  depends on other code layers, both for data presentation, as well as
  application flow - and those aren’t Ajax at all. Thats why you don’t
  see web apps purely based on it - it’s simply impossible.
• The percentage of Java (some people still confuse Java with
  Javascript) being used on the web is declining, and has been since
  alternative - and far lighter - technologies (like Flash) came along
  that removed the need to load a JVM to do what Java used to do. In
  fact, why would I, as a developer, pick Java over anything else that
  allowed me to do the same thing and not frustrate my users by slowing
  their machines down a notch?

Tim O’Reilly concludes the post with this sentence:

It’s impossible to think through what people are going
to want to do until they start doing it, so sometimes it’s best to seed
the market with a hack that gets people going, and then follow up as
you watch what they do with it.

Tim, the major problem here is that the time for Java-based
front-ends on the web is gone. Others have emerged in this space and
took its place, not because they were “hacks”, but because they were
better solutions to the problems developers faced. Why should anyone
change from Rails+Ajax (or anything else+Ajax), Flex or anything else
to Java? What does it really have to offer that we haven’t seen before?

And I mean on the web, Tim. Because the application you mention on
your post isn’t web-based. It’s desktop Java, using Swing. There’s no
competing with Ajax, or anything else on the web, because they’re not
even playing in the same field, here. Let’s not compare Apples to
Oranges, or hype technologies because the enthusiasts behind them
(which I respect, naturally) are feeling angst for their ball being
taken away, not by hacks, but by several other solutions which people
have grown to use.

Update:

After reading some comments (and getting some IMs), I realized I
didn’t make a proper distinction between what I meant with the time for
Java on the web being gone. It’s not the server-side Java I’m talking
about. What I *am* talking about, though, is Java as a presentation
layer for web applications, the front-end, the frickin’ applets - which
is what Tim was talking about as well. This being explained, my point
may be clearer.