I do see the potential however with the of hacks and closures of traditional exchanges that go on (Bitfenix, Mintpal, Cryptsy, etc.)...not to mention the DDoS attacks that go on with Polo at the most critical high volume/high price movement moments when you really need your orders to execute.
Still, though, if the success of Blocknet relies on the failing of other exchanges it may never catch on. It will need to have the same level of ease of use. Having a quick easy way of checking the order book seems like low hanging fruit for a step in that direction.
100% agree. Some people don't seem to have a problem with downloading the blockchains but I think for it to get any decent amount of users it needs to be really easy to use, like you say.