Nope. It's not a couldn't thing... it's a wouldn't thing. Since Harley isn't permitted to introduce any new models (the V-Rod proved that), the only thing their troglodyte core demographic will permit them to do is to keep dusting the showrooms with new variations of blacked out and pre-chopped "customs", based on existing machines.
Honestly, even factoring in the Rocker, the only thing they've done that really seems worth a damn - as far as custom models of existing bases is concerned - is the Fat Bob. Now THAT is a kick-ass dyna variant.
I would love to be sitting in Erik Buell's seat for a while. Or someone else int he company with enough F-U money and pull available. Their engineers are pretty kick ass; they're able to deliver a perfectly modern and serviceable machine wrapped in "classic" styling. Just imagine if all that "heritage" was permitted to fall away and with their marketeers' blessings, something with true broad appeal could be developed.
 heritage is actually a Greek word that means "that which holds back any and all progress toward the 21st century".