Skype announced the appointment of Tony Bates as its CEO, joining from Cisco where he was a senior VP and general manager of its Enterprise, Commercial and Small Business Division. The company did not state what is happening to “outgoing CEO” Josh Silverman, who “has been instrumental in maintaining Skype’s momentum and growth.” Meanwhile Twitter appointed Dick Costolo as its CEO, moving up from the COO position. Incumbent CEO and co-founder Evan Williams is now “completely focused on product strategy.”