A lot of people see that MaidSafe's vision has loads of potential, and if it can work, it could be a game changer. However, nobody is certain that the Safe network will be possible in the envisaged form, so anything that removes technical risk could have a big impact on price, as the likelihood that the Safe network will be a game changer increases.
Alpha demonstrated most of the required tech working in a controlled environment, which reduces the risk. The next Alpha should demonstrate more refined tech working in a less controlled environment, plus with more eyes looking at it.
If that's a success, the chances of the Safe network being realised increase, which should positively affect the price. Following this successful test net, I'm also hoping confidence begins to rise, which should reflect in the price.
However, there were other pumps pre-alpha that seemed to have nothing to do with specific events, so we'll just have to wait and see how it pans out.