There may be some merits to the technology but the problem with Silverlight is support--the same reason people are upset in this thread. Microsoft has a history of leveraging their strength in one division to propagate their position in another. The internet is a great example; it's the reason for the anti-trust cases brought against them by the US DOJ and the EU. If Silverlight had the marketshare that Flash currently has, do you really think Microsoft would offer support without any deference to platform? Maybe I'm a bit cynical, but I don't think competitors to WinMobile would be equivalently supported. At least Adobe has an interest in supporting as many devices as they can equally.