I have written before a short comparison between "old" and newer technologies, but at the beginning of that post I state that part of the choice of a new technology is the market trend towards that technology.
After reading Justin's post showing that moving to ASP.NET is beneficiary because it's becoming a prominent technology I decided to implement his research methods (using Google) on different technologies.
I began by searching for file types
However, this reflects only on files shared on the web, and since JAVA is a web technology (unlike Delphi) the results don't say much.
But Google trends provides a clearer picture - while C# remains stable, other programming languages are on the decline:
Focusing on the .Net world, you can clearly see new technologies are dominant in Google searches:
WPF vs. Winforms
WCF vs. Remoting
With Silverlight being the "Hot New Thing" (maybe because it's a web-based technology)
So maybe choosing a new technology is a logical move even if it doesn't offer a significant technological advantage - since keeping older technologies means you are working against the market trend.
So consider switching from Winforms to WPF, from various communication technologies to WCF and from VS 2003 or 2005 to VS 2008 - in the long run the market will force you to do it anyway, either through the job market or through customers demands.