Over view:
Fueled by remorse and vengeance, a high schooler named Terry McGinnis revives the role of Batman. Under supervision of an elderly Bruce Wayne, he fights crime in a harsh futuristic Gotham.
With Christopher Nolans Batman trilogy coming to an end I think this would be the perfect time for a Batman Beyond trilogy; this way you could have some what of a continuation with the series without actually having to reboot it.
Here is an example of what I would think the Batman Beyond bat suit would look like-
BATMAN/TERRY McGINNIS:Milo Ventimiglia
Milo is a talented actor he has shown that he can be the heroe on the show heroes and have the personality of Terry.He would work well off of Harrison Ford barking orders at him all the time.
BRUCE WAYNE:Harrison Ford
Harrison Ford is one of the greatest actors of our time and he is starting to show his age the role of the elderly Bruce Wayne would be perfect for him. He would've made an interesting Batman in his younger days.
COMM.GORDON:Helen Mirren
Helen Mirren proved she can take charge and have some serious leadership and fighting skills in the movie red; her character in that movie reminded me of an older Barbara Gordon. She would make Gary Oldman proud as the next Comm. Gordon.
WARREN McGINNIS:William H. Macy
William is one of my favorite actors and an under used one in hollywood these days the part of Warren would be ideal for him and he looks like him to.
MARY McGINNIS:Geena Davis
Geena Davis is the ultimate mother figure having portrayed a mother on screen before previous films the role of Mary would suit her well.
MATTHEW McGINNIS:Preston Bailey
This is the perfect role for a relatively unknown child star; Preston Bailey would own the role of the annoying little brother. He can be seen in the 2009 movie "Children of the corn."
DANA TAN:Mila Kunis
This part was made for Mila she looks just like her and would be a good female lead for the franchise.
MAX GIBSON:Chyna Lane
Chyna is an upcoming young black actress and can be seen in the movie "Precious" Max could be a break out role for her if played correctly.
DEREK POWERS/BLIGHT:Jason Isaacs
What can I say Jason is the ultimate villain and would do well as the bad guy in any movie Derek Powers/Blight would be a good move for him. He would own the role and give it a new dimension.
Forshadowing of things to come...
Like in the Dark Knight the Joker was the villain of the sequel. The Sequel to Batman Beyond could re-introduce the Joker through the "Return of the Joker" storyline.
THE JOKER:Mark Hammil
This would be the perfect chance for Mark to portray him on screen as a slightly older Joker; but with a youthful appearance.