We are optimizing only Telerik dlls at the moment. I don't think it will be a problem when we optimize the system dlls that we are using in the XAP. The market place should use the new optimized dlls and not to care too much about that.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items