You don’t mention whether your company is committed to Windows and/or IIS and/or SQL Server. Obviously .NET would have a stronger claim in that case, compared with, say, a Linux/Apache/MySQL environment.

Cost: clearly there is less cost associated with an open source technology stack, so Java wins on that count (despite what Microsoft might say about total cost of ownership). Also, if you want to use libraries for things like report writing, you’re more likely to find something good but free in the Java world than the .NET world. This is less true than it was, though. For example, the iText library for PDF generation has been ported to C# and it works very nicely.

Performance and reliability: we really haven’t noticed any difference in application performance. Although I must say the C# compiler is unbelievably fast.

Flexibility: both Java and C# are very general-purpose languages that let you do practically anything - but see other points below.

Development times: it depends on what type of application you’re developing. If you want to build very simple, straightforward applications and are prepared to sacrifice some control over the nature of the code, Visual Studio .NET can generate something very, very fast. I don’t think there is anything in the Java world that can quite do this. But if you want to do “proper” coding, there isn’t much difference - Java and C# are very, very similar.

Data tier integration: if you want the best possible support for recent versions of SQL Server, .NET has to be better. We’ve had our fair share of problems with JDBC drivers. (If you’re using Oracle, the opposite may be true?)

Support: the only comment I would make here is that, as a group, .NET developers seem to be very Microsoft-centric in their experience and sometimes have a tendency to swallow the MS approach whole rather than picking and choosing the most appropriate parts for a given project.

What you won’t find in either case, sadly, is the kind of online community that you get with House Of Fusion - that’s unique I think.

Tooling: I’m not a big devotee of visual tools, but Eclipse and Visual Studio both do the job.

Help with CFML development: well, neither of them helps specifically with CFML development. Obviously you can integrate Java code into a CFML application, which is great. And you can run J2EE apps and CFML apps within a single environment. Then again, I believe you can do the same with BlueDragon for .NET.