Delphi is a great tool, but language/tool does not matter much anymore.
If this was around year 2000, Delphi was lightyears ahead when it came to native Windows development with rich user interfaces, while still giving you complete access to API, assembler etc. if you really wanted it, but many other tools have caught up now. (Although most then require either .Net or Java, but I don't see that as a major problem really.)
I still prefer Delphi for Windows development (and hoping with its later incarnations + FreePascal I will get time for crossplatform some day) as it is still a great tool with lots of productivity in it, but C#, Java etc. are all good as well. Each language/toolset/libraries has its own advantages, but they can all do the job you need done!