Some libertarians see him as our best hope, while others just think he is a republican marketed as a libertarian to get young voters.
Rand is an interesting case... The cynic in me thinks he is riding into the libertarian camp waving his father's name as a truce banner but not really meaning it, and the optimist in my thinks he is "playing the game" so to speak, something his old man never really got right. The realist in me thinks Jeb Bush is going to get the nomination and nobody with Paul as their last name will ever get through a primary anyways. Is Rand perfect? No, of course not. Is Rand a politician? Yes. Does Rand stink as much as the rest of the pack? Mmmm... I would say no. I promised myself I would never hold my nose when I vote, and I think I'll be able to do that with Rand.
I don't know if I could vote for him, because I'm a pretty dyed-in-the-wool socialist when it comes to a lot of things, most specifically economics. Part of his philosophies I agree with- like auditing/abolishing the fed, but I like social programs and regulation. I feel that corporations are a large part of why our economy is so one-sided these days and I'd like tighter regulations on financial institutions, not laxer (is that a word?) ones. I'm also very pro-national healthcare, and Paul obviously is not. Finally, he's anti-abortion and anti-same-sex-marriage, which seems to be pretty disingenuous for a so called libertarian. It's cool that there is a famous politician that's anti-drug war and wants to reduce foreign aid (especially to Israel) and military activity abroad. EDIT: Oh, and if this question was for libertarians only, I apologize. I'm only a quasi-libertarian really.
I'm pumped for Rand Paul. More than anything what Libertarians need is someone to introduce the cause to the general populace. For a few reasons it's important, but one major reason is to thin out the extremists that speak loudly for the camp but don't actually run or participate in campaigns. People who don't believe in compromise are not someone who I want to ally with. I think Rand Paul is running as a Republican because like it or not, there isn't going to be a Libertarian President until more people know what Libertarians represent. If half of your campaign is spent just explaining what your party is, then you're never really going to get to the issues in a large scale election. Ron Paul bit off on explaining the basic tenets of Libertarianism all the time, and it got him down into the minutiae of politics when his opponents got to speak in broad strokes. You can convince one person with details, but one person isn't going to win an election and so you're better left to broad strokes and relying somewhat on your party's affiliation with issues. It's a huge luxury that Libertarians just don't have yet.