Ron Paul is still in the running (kind of).
His supporters love him, there's no doubting that. He's got a bunch of people excited about his 'We are the Future Rally' set to take place in Tampa in tandem with the RNC. His main goal seems to be to try to set party platforms with the delegates he collected and support he's garnered across the country.
You can see details about his rally here: http://www.ronpaul2012.com/2012/07/06/ron-paul-tampa-rally/
I don't know that he'll have a large impact on what Romney and Ryan set out to do. Whether he runs as a Libertarian or a Republican, he does have some strong ideals that he's consistently clung to over his career, and for that consistency he has many people's respect, including my own (this does not mean I think I will vote for him instead of Romney).
Some people think he'll try to wedge in a speaking spot for his son Rand, as they try to gain favor with party leaders so that they can further their national goals in the coming elections. I guess we'll see.
Whatever the outcome is for Paul post-convention I think he's an interesting and noteworthy political figure to keep track of. If he does not go on the ballot officially for the national election in November, which I think is unlikely, it will also be interesting to see how many people write him in in order to spite the establishment political parties and candidates.
I don't know that voting for Ron Paul is a productive vote, but is is a way to signal the establishment parties of your discontent.