George Jackson would have acted less radically and violently today, not necessarily because we live in a post-modern and more equal society, but because culturally, our times are a lot different from what they were 40 years ago. The 1960s and 1970s were overall a more violent, volatile time. This was an era when a lot of people were turning to political violence and radical ideas to counteract and fight against what they thought was the "establishment."
In the 2000s, there's less of that type of rage that led to the radicalism and violence we saw in the 60s and 70s. In fact, all forms of radicalism and violence kind of fell out by the 1990s (note how you don't hear about the Nation of Islam or abortion bombings anymore). Given how much more calm and level-headed everyone is today, I can't see someone like a George Jackson resorting to violence and becoming radical in response to today's problems.
Yes, George Jackson the Black Panther would have acted so radically and violent in today's post-modern and more equal society, because there are still Black Panthers in today's society. Some Black Panthers even have the support of Eric Holder and the U.S. Department of Justice. No matter how equal we might be there are some people who will never be happy.
No, George Jackson wouldn't have needed to be so violent in his search for equality if he had undertaken it in this era. People are more likely to be heard if they act through the court system these days instead of using violence or threats. A civil law suit would have a much greater impact on society and to Jackson personally than a prison sentence.
Black violent radicalism that produced the Black Panthers was a product of it's time. This was the era of Vietnam war protests, civil rights activism, race riots, and general social upheaval. None of these conditions hold at the present time to foster the formation of this type of movement. It was a product of it's time.
I do not believe George Jackson, of the Black Panthers, would have acted so radically and violently in today's world. Obviously some of the actions of the Civil Rights Movement made today's freedoms possible and it is hard to say which actions really got the movement in place, however in today's age there wouldn't be as much stimulating problems to let the organization evolve to the point it did back then.