Things definately look bad for WB and his allies at the moment. Luffy surely can't hope to defeat all admirals at once, so maybe we'll see a surprise entry, say, Shanks or Dragon?
i think its too early for Shanks and Luffy to meet i want that meeting to be under happier terms but Dragon i can see.. seeing as there are several revolutionary members already fighting as well as his son and a chance to take down the marines/WG.