I had to write a rebuttal to this post. It’s not up there yet, so here it is now:
Although you have pointed out some valid grievances with SL we may agree upon, I think overall we have a large disparity in our opinions.
1.) Text being selectable in a browser comes from the browser's historical utility of being a document browser, not an application development platform. I don't feel all applications should also double as documents, do you?
2.) Yes, right click is not there. Yes there are ways of making it work, but I don't see how this is a deal breaker for Silverlight or hold weight for the "not taken seriously" argument.
3.) Printing is a disaster in SL3 but looks likey for SL4.
4.) SL3 comes with over 60 controls...and I commend Microsoft on the SL toolkit on codepex. Why? Doing out of band control releases allows Microsoft get controls to developers outside the primary release schedule of Silverlight. It allows the community to submit bugs and feature requests. When the controls mature, they get added to the official package. Sounds like a win/win situation. Microsoft doing open-source development *gasp*!
6. Microsoft is _not_ trying to compete with AIR at the moment, though I can see how people perceive this. OOB is made for adding offline/out-of-browser support of your application. I'm sure Microsoft would much rather you use WPF if you are trying to make a richer desktop experience. Much like the right click argument, I don't see how this takes away from Silverlight's credibility and one may argue your end users would rather not have to deal with popups
7.) Now you are getting petty. If you don't like the default control template in VS, then edit it! This is like shunning a word processor because loads up using font_you_dont_like.
8.) Maybe you didn't hear, but SL3 supports more than GET/POST. Check out the new networking stack this much more RESTful. Don't forget SL also supports SOAP, so yes, you can do business apps the "right way".
Sure you will find some reluctance with companies using Silverlight on their website in the same way they'd use flash, citing install base. BUT, enterprise/business applications are a whole other game than just a "website" with random users dropping by.