A fellow MVP once mailed: “I’ve got friends that were heavy into SLdevelopment that now do none. It’s gone from their #1 technology to now being banned for development within their company. What changed? The first time that one of their clients said “now show me how it looks on my iPad” and they had no answer.”
I think this counts for every plugin based technology (Flash, Java (to some extend)). The success of the iPad and the combination iPad/Safari shows the vulnerability of tooling that depend on functionality of browser plugin’s.
I think it is not wise to advise a plugin based technology in case of a SAAS product. But when it is about a on premise solution with a firm control on hardware/software or it is about the control console of a big device (which does not need to be remotely controlled), then I would certainly build it with Silverlight.
Also when ‘bring your own device’ (where device can also be a browser of choice) is a policy, that makes plugin based technology not first class choice of a no brainer.
A customer of ours is building a SAAS product and they choose to develop it with Silverlight. Their reason was it is a mature technology and they can demand the use of the Silverlightplugin. Also important was the possibility to go out-of-browser with application.
For mobile devices it will probably never be, that all the functionality of the application is made available for such platforms. Mostly it will be parts of the product, where the pro’s of the device can be used fully. iPad is special where it is about the web browser. The other current mobile devices have to little screens, on which the complete functionality is barely possible and hardly useable.
My opinion is the choice between Silverlight and HTML5 is not black and white choice.
I love to hear your opinions in the comments.