oh .... well then what's the point of a commercial license? You'd only need it if you customize the original Qt source code and don't use it as-is, right? Or if you want support beyond forums/mailing lists?

Yes, but customizing and patching is not that uncommon for commercial software (Qt is used a lot in the embedded space, for example, where patching and shaving away is common).

Also, businesses do pay for support as insurance; say tomorrow Windows patches something that screws up a bit of Qt your product depends on, what are you going to do? Waiting for a reply on a random mailing list and hoping someone has time to fix it, is not going to cut it.

As usual support and there are some libraries in the Qt Umbrella of source code that ARE NOT LGPL and you can't use those for distribution unless you pay for the commercial license.