Well, Yahoo! has already officially announced its $1.1 billion cash deal to snatch up social darling and microblogging platform du jour, Tumblr. The question on everyone's mind is, what else could the struggling web pioneer have up it's sleeve? Truth is we have no idea. Could Mayer have another acquisition to announce or a special new product lined up for tonight's event? Or, is she simply going to talk about the finer details of the Tumblr deal for an hour. You'll have to check back in at 5:00pm ET to find out.