Am I the only one who considers Perl6 dead and irrelevant?

No, lots of people have expressed that opinion. But, the reality is that Perl (5) is still more popular than Ruby and Python (probably combined). I suspect that if anything really derails Perl, it won't be Ruby or Python.

It also certainly won't be Java or D, which are going after systems-level development tasks, and, in the case of Java, accidentally ended up being somewhat popular for poorly fitting tasks, like web apps. Perl and Java, actually, pretty much came along at the same time, and both have coexisted mostly peacefully at two ends of a spectrum for many years (and now, over at the Perl end, though maybe not quite as far down the road, Ruby and Python also coexist mostly peacefully).

I suspect that if anything derails the popularity of Perl it'll be that JavaScript will have a good server-side implementation before Perl 6 becomes a solid reality, and it'll also derail Python and Ruby from ever reaching a level of true pervasiveness (on the order of PHP, which will also lose out significant market share). And, of course, this theory only applies to web apps, where the current server/client dichotomy is less comfortable than it should be, that this will make any sense at all, and it doesn't mean any language will stop being used for web apps, at all. Millions of lines of code don't stop existing overnight. I just think that when the choice is between "use one pretty good language on the client and server" or "use my favorite language on the server and a pretty good language on the client and try to make it all fit together seamlessly" and apps become more and more rich on the client-side, it'll end up being obvious to choose the single language option.

Of course, a lot of software is not a web app, and so there will remain systems-level languages, and dynamic languages for various types of text processing and other such things, and Perl and Python and Ruby will be among them. But, if a good implementation and good libraries show up for JavaScript on the server, it will have a huge impact on all current web application languages popularity.

Another interesting game changer is dynamic languages on the JVM and CLR (and, probably, Parrot). I suspect that will also have a dramatic impact--but it won't lead to the death of any language. It'll make more languages flourish, as it removes the requirement that a language have a reasonable standard library before it can gain any traction--the library will be "anything else that runs on that same VM".

is irrelevant as all the kids will be using Python, Java, Ruby, maybe D

The kids are already using Python and Ruby. It doesn't mean kids aren't also using Perl. And, of course Perl 5 hasn't been sitting still...5.10 has some nice new bits and pieces pulled back from Perl 6.

Legacy applications won't switch from Perl5.

They won't have to. Like all Perl versions for the past 10 years, or so, Perl 6 is backward compatible. It's possible to "port" a Perl 5 app to Perl 6 instantly, and then begin making use of Perl 6 features as appropriate. Of course, you won't get the benefits of Perl 6 in sections of your code that are Perl 5, but they can be ported as time allows and as refactors happen naturally.