I'd love to see it done, but as has already been said it'd have to be done by somebody like HBO, and as a continuation of the Nolan films (hopefully after a third
) keeping the dark theme and style of interpretation of villains.
I wouldn't want to see too many episodes - a couple of series, ten episodes each may be more than enough - how many times as a really good series been spoiled by overkill?
Also, the TV series format means you could develop characters and villains better over the longer period. You could establish characters that may not play a pivitol roll till late on in the series.