Pure Technologies offer open-source PureSOAP, which looks like a good way to use SOAP from Delphi, without require the Enterprise edition of Delphi 6. Another good approach for this is to use Microsoft’s SOAP support (ROPE, etc.) via COM.
DUnit is a Delphi version of the “xUnit” familt of unit test tools popularized by Extreme Programming adherents. I’ve found it quite useful even on projects that have nothing to do with XP. I tend to be skeptical of any significant body of code for which there is not a test suite.
Around the same time you automate your testing with DUnit, take a look at FinalBuilder for automating your build process in Delphi and other Windows IDE-based tools like help systems, installation systems, etc. I haven’t tried it myself yet it looks quite appealing.
Since the Kylix annoucement and arrival, there seems to be an abudance of people eager to use Delphi with non-Microsoft technolgoies, and I am pleased to see Delphi expand into the Linux world. We shouldn’t forget, though, that Delphi is superb for developing software using Microsoft technologies. For example, I have heard of companies doing all of their “heavy lifting” in COM objects written in Delphi, while using VB or ASP to put together overall applications. For more on Delphi with Microsoft technologies, see MSDelphi.com.