I believe there will be because third parties have had success in the past. I believe the democratic and republican parties have become too homogenous to fairly represent the majority of voters (don't believe me? Explain why, in 2002, 90% of the House seats ran either virtually or completely uncontested).
The truth is, voters are looking for new answers, new solutions. The major parties aren't providing them. As a result, I believe we will see not one, but two or three power shifts in the political parties over the next 30 or so years. Since 1992, at least one minor party candidate has controlled enough power to make a ripple in the election process, and I believe it's only a matter of time before savvy voters "rally around the flag" so to speak, and a candidate appears on the scene who is both electable and adequately funded.
As well, I believe the internet is the "x" factor. Unlike TV advertising, internet distribution of one's platforms comes only at the cost of time.
An interesting side note: please note the minor party results in New Hampshire, Wyoming, Montana, Idaho, New Mexico, and Nevada (possibly Utah). I have very solid reasons to believe you will see some strong numbers from the Libertarian Party candidate (Michael Badnarik) in one, if not more of those states.
Excellent topic!