The momentum wouldnt stop, people who know about it and use it now will know the new name and thus continue to use it, the general public who haven't heard of it yet (but more than likely heard something about some funny internet money that got hacked, this stuff sits in peoples consciousness, there, but not enough to recall) will learn it by the new brand, something that doesnt confuse the hell of them. How many times are you met with utter confusion when you try and explain bitcoin "but how do computers make money" "who gives it the value" - calling something a coin that is not actually a coin, it just the first mental trip wire that goes on in peoples heads (in my opinion, based on nothing but my own view point,observations and life experiences)
"What's in a name? that which we call a rose, by any other name would smell as sweet"
Also, I think a rebranding project might actually run better than a lot of big companies do, I mean, its open source, shit gets done when everyone chips in.
I think any publicity is good at this point... the time table for mainstream adoption isn't quick. We're talking at the very least a couple of years (more likely 5 or 10). So while publicity from sr and ponzi schemes seems bad right now... if a few year or 5 or 10... then it becomes an asset to bitcoin, because the network and the community survived it. just my opinion tho.
If you do start a rebranding campaign - that's an epic undertaking, you've have to get pretty much everyone on-board with that or it wouldn't stick.