The reason I got interested is mostly related to wp7/silverlight development.
The problem with silverlight class libraries is that you cannot use them with the normal Unit Test packages. To be honest, silverlight testing is pain the rear. When portable library came into existence it allowed me to push significant part of functionality
into portable libraries with decent unit test framework.
You're right, you indeed would have to give up on lowerbound and decimal type. I actually downloaded your code and tried to do exactly that - cut out these features and compile sharpSerializer as a portable library.
When I looked at source control I found out that I modified:
I ran over the budget of time I gave myself to do it (4 hours). So now I am using standard serialization provided by the silverlight runtime though I think sharpSerializer is a better fit.
sharpSerializer is a great product and not having support for the portable lib is definitely not a show stopper but I think it is reasonable to have a portable library without these two features, and two more libraries built against .Net
and Silverlight with the features.