I understand from Greg McCaskle's answer that this is something which may come in future (And judging how far LabVIEW has come, I'm sure it will be incorporated).
If you're developing code in other languages which create COM-compliant DLLs, then is it not possible to write a wrapper DLL in this other language and register this instead... I agree that this would be a nice thing to have, but even without it, LabVIEW has established itself as a powerful tool for test and measurement. If you need ActiveX-enabled DLLs, then at the moment you should use another language to do it. The right tool for the right job and so on. Shane.