I would have to say I disagree....I'll admit, in the beginning it took a lot of effort for me to sell the benefits of using DotNetNuke and yes, I did a little re-branding ( I called it DNN). At first my users hated the switch and wanted nothing to do with it...They think they lost control, which they didn't. And I swear DotNetNuke was a curse word for awhile.
After a few month of positive reinforcement and support, they finally got it. They are impressed that the can have new functions by simply loading a new module, where it used to take a programmer to create that function for them...turn around time is 10x better than before...Now some complex functions do take a developer to maybe tweak a module or build a module, but it's the turn-around time is still better than starting from scratch.
Now in my organization, DNN is very well thought of. It took me a awhile to get this point and I really think re-branding now would be a mistake and the community in general would lash out as well.
In IT, anymore you have to have skills in marketing, public information, salesman and education because you have to sell it/support it on so many different levels. And I agree Joomla and Drupal are dumb names too, but it doesn't make difference because it's based on perspective...if you can't make your point and sell yourself and your system, then it's not the system's fault.
You need to re-think your strategy and approach....rebranding now would be a mistake...good or bad DotNetNuke is gaining momentum and mindshare.