I voted October, but that's just wishful thinking. Even if there were some refresh soon, I don't think it would be what we're waiting for. I think it unlikely that we'll see 8GB RAM in any Mac but Pro until the release of Snow Leopard (I know Leopard can deal with it, but I still think they'll wait), and unless they decide to narrow the gap between MacBook and MacBook Pro by offering all three lines with 4GB RAM, they won't be offering Air with 4GB. And while it's practically certain there'll be 120GB HDD, I don't think 128GB SSD is going to be available so soon (far too expensive still), unless as a very costly option.
I hope I'm wrong.