There may be a future for electronic voting, but right now there's too much uncertainty:
As Dan Wallach (a Computer Science professor at Rice and a world-recognized expert on voting systems) eloquently put it, election security is a national security issue. The computer security field has intensely studied the problem of conducting elections for more than a decade. From the very beginning of this effort, the computer experts have almost universally agreed: we can’t secure purely electronic voting systems. It may be surprising to outsiders, but computer scientists believe in paper ballots, either directly marked by the voter or created by a machine and placed in the ballot box.
Voting systems need to convince rational losers that they lost fairly. In order to do that, it is critical to both limit fraud and have the result be easily explained. It is impossible to prevent all fraud but we must ensure that the cost of fraud scales with the size: it should take 100 times more effort to change 100 votes compared with the effort associated with changing one vote. Any voting system in which fraud is constant—that is, in which changing 100 votes takes the same effort as changing one—must be viewed as critically flawed.