Man, they are on some buying binge. Unfortunately for them, I don't think it's possible to buy innovation or relevance. Those things have to come from within and permeate the entire culture of the firm - and Yahoo just doesn't have it right now.
http://en.wikipedia.org/wiki/List_of_acquisitions_by_Cisco_S...
They seem to be doing well.
http://money.cnn.com/magazines/fortune/fortune500/2012/indus...
Cisco actively encourages senior engineering employees to leave the company, start new ventures and return as leaders in the M&A process. It's not fair to compare Yahoo to Cisco when Cisco invests tremendous amounts of effort, time and money into these ventures to grow and nurture them (recent example: Meraki) until they can be reabsorbed into the Mothership.
Yahoo on the other hand is buying a bunch of companies that it knows only by reputation. Yahoo might be successful, but not for the same reasons that Cisco is successful. It's just a very different culture.
Innovation is possible by acquiring already-innovative companies and letting them flourish as if you hadn't bought them, then stick your name on the work they produce.
Relevance is even easier, just throw $1.1 B and you're going to be the thing that's relevant. At least for a little while.
Is it ideal? Can it scale? Will it last? No, but it gets the job done.