There's no question BobMu has done fantastic things with the STB franchise. He has a bit of egg on his face lately (VS 2010 / DotNet 4 slips & bugs, the oft-quoted Silverlight interview, PR fallout from the DE "announcement") but it's hard to believe
those would be enough to demand his resignation. More likely this is part of a much larger reshuffling at the highest executive levels, like the article alludes to.
It's very very unlikely this change carries any direct impact on Vail. WHS is a small product compared to Windows Server, SQL, Exchange, VS, TFS, BizTalk, Sharepoint, etc etc. Besides, there are 9 levels of management between a typical developer
on the front lines and the President. And most importantly, it's too close to shipping for any major course corrections. (ahem)