over the years i have been employed in a permanent position with firms that did their development work in Windows SDK, VC++, and most recently Java; in my own eyes, I am language independent.
Should I move from Java to Delphi (assuming pay-scale remains unchanged)?
I'm concerned because, for the most part, the net presents a relatively bleak picture for this particular skill.
It never hurts to pick up another skill, but I haven't seen any Delphi job listings anywhere. I suspect you would be better suited picking up a new language/framework/platform with more "legs", such as WPF, JavaFX, Objective-C/Cocoa, ActionScript/Flex, or something of the like.
As a technical move, it's probably a good one -- Delphi is better thought out and more enjoyable to use. From a career perspective, however, you're probably right -- Delphi has been rather marginalized for some time now, and doesn't seem to be in the process of making a huge comeback.
The way you phrase your question makes me think you've got a job offer already for a Delphi developer position. If the language is the only thing stopping you, I say you should go for it.
It will add experience with another language to your resume besides being fun (learning something new). Just make sure you keep your skills in Java and C++ reasonably up to date when or if you need to move on.
Depends on what your goals are, but I believe that for regular apps the future bears name "GWT", i.e. Java. (I consider Delphi a history for quite a while, but that's JMO.)
The TIOBE Index is an often cited source for estimating the popularity of programming languages. Java, C and C++ have been the top 3 for a very long time. As you can see, Delphi is a lot lower on the list (at position 10 at this moment). (Ofcourse you should not take the TIOBE Index as an absolute measure, but it does indicate something).
This can be an advantage as well as a disadvantage. There are probably a lot more Java and C++ jobs than there are Delphi jobs, but there are also a lot more Java and C++ programmers than Delphi programmers, so it's harder to stand out as a Java or C++ programmer among the masses. Having a specialism that not many people have, such as for example Delphi, may help you get a higher salary, though you'll have to search harder to find Delphi jobs.
It's definitely worth learning Delphi. A lot of software's still being written in it, stuff which people use and rely on. A lot of companies prefer to keep quiet about it, though, since it presents such a major competitive advantage over other, more popular languages.
For example, you ever work with VOIP on chat programs? In my experience, there are two basic categories: Skype, and The Other Stuff. Skype "just works", while the others tend to be very glitchy and unreliable. And it's no coincidence that Skype's written in Delphi while (AFAIK) none of the other chat programs are. That's just one example among many.
Why limit yourself to one language?
A major problem with Delphi is that some people consider it an "easy" language. So there are Delphi programmers that can drag some controls to a form without any real coding knowledge. So if you are a good developer and skilled in Delphi, you won't have that much trouble finding a job.
I was using Delphi before I swtiched to C++ and then to Java. I don't think that moving from Java to Delphi is wise idea. Why so?
The only good reason for preferring Delphi over Java I can actually think of is making Windows GUI application. But since we have .NET and wonderful WPF, Delphi doesn't score even here.
You make your choice, but personally, I'd never switch back to Delphi (ok maybe if payment was too good to reject:))