The VPs had one job in their debate; defend their Presidential candidates.
My initial thoughts (listening to it on radio twice) is that Pence defending Trump and Kaine did a good job defending Clinton and got some jabs in on his own. Kaine came out ahead.
Pence mainly denied things that Trump had said, while Kaine kept pointing those things out. That made it hard for Pence, who doesn't really support most of Trump's opinions. But given that, Pence did the best he could, and in a technical sense, skillfully. He has set himself up as the top contender for the Republican nominee in 2020.
But he will face most of the losing Republican candidates of 2016 , so it will be another crowded field.
Kaine did a good job of defending Clinton, Obama, and Democratic positions in general in general, so he has a future also. Whether an elected VP, or the losing one, he did well enough to establish himself as a leader in the party. Obviously, being a winning VP will be better than a losing one, but either way, he is "noticed".
If Trump wins and fails at leadership, the 2020 election could well match Pence and Kaine and I'm sure they are both planning for that. Or if Clinton wins, as seems likely, Kaine will bide his time as VP and go for the Presidency in 2014.
But overall, Kaine won because he supported the likely next President and Pence won because he represented the conservatives who hate Trump.
This election might be the last of the Boomers, with Clinton. The next might be even more contentious.