I may be paranoid, but it seems quite plausible to me that Silverlight is merely another example of Microsoft's famous "Embrace, extend and extinguish" strategy. Since Silverlight failed to gain wide acceptance on the web (well, certainly not as wide as Flash), acquiring Adobe to get hold of Flash would enable them to skip the part where their software first needs to be accepted by a significant majority of users and allow them to skip right to phase two, which is concentrating more and more on how Flash works on Windows and IE, leaving other platforms and browsers behind. Truth be told, Adobe has also been known to concentrate more on how their plug-in works on Windows than on other platforms, which meant that Flash would usually perform far better on Windows than on Mac OS or Linux.